bump pointer: internal (D-320, concept docs, plan oobe-update-outcome-and-late-start)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.github/scripts/Get-StorageAuthHeaders.ps1

@@ -11,6 +11,7 @@
     Identity comes from whatever `az login` established: the federated GitHub OIDC principal
     in CI (azure/login, subject repo:okieselbach/AutopilotMonitor:ref:refs/heads/main), the
     operator's own account for the local build. No secret is read, stored or passed around.
+    Under GitHub Actions the token is masked in the run log before it is returned.
 
     x-ms-version is MANDATORY here, not decoration: Entra-authorized requests are rejected
     below 2017-11-09, and Table requests without a SAS must carry the header at all. 2021-08-06
@@ -45,6 +46,15 @@ if ($LASTEXITCODE -ne 0 -or [string]::IsNullOrWhiteSpace($token)) {
            'on the table -- a missing role shows up later as HTTP 403 AuthorizationPermissionMismatch.')
 }
 
+# GitHub masks only secrets.* on its own; a token minted at run time is clear text in the
+# (public) run log the moment anything prints it -- an uncaptured call of this script, or
+# Get-Error / Format-List on a failed request, whose TargetObject carries this header.
+# Write-Host, never Write-Output: the output stream is this script's return value. Only
+# under Actions -- anywhere else the line would print the token instead of hiding it.
+if ($env:GITHUB_ACTIONS -eq 'true') {
+    Write-Host "::add-mask::$token"
+}
+
 return @{
     'Authorization' = "Bearer $token"
     'x-ms-version'  = '2021-08-06'

.github/workflows/deploy-web.yml

@@ -108,6 +108,8 @@ jobs:
           NEXT_PUBLIC_ENTRA_REDIRECT_URI: ${{ vars.NEXT_PUBLIC_ENTRA_REDIRECT_URI }}
           NEXT_PUBLIC_ENTRA_POST_LOGOUT_REDIRECT_URI: ${{ vars.NEXT_PUBLIC_ENTRA_POST_LOGOUT_REDIRECT_URI }}
           NEXT_PUBLIC_API_BASE_URL: ${{ vars.NEXT_PUBLIC_API_BASE_URL }}
+          # Browsers load the live stats through it, and the build reads it once to bake the
+          # numbers of this moment into the landing page's static HTML (lib/platformStats.ts).
           NEXT_PUBLIC_PLATFORM_STATS_MANIFEST_URL: ${{ vars.NEXT_PUBLIC_PLATFORM_STATS_MANIFEST_URL }}
           NEXT_PUBLIC_APPINSIGHTS_CONNECTION_STRING: ${{ secrets.NEXT_PUBLIC_APPINSIGHTS_CONNECTION_STRING }}
           # Build stamp for public/version.json (scripts/generate-version.js in prebuild);
@@ -121,6 +123,9 @@ jobs:
           npm run build
           test -f out/version.json || { echo "out/version.json missing - export did not run"; exit 1; }
           test -f out/whats-new.json || { echo "out/whats-new.json missing - whats-new prebuild did not run"; exit 1; }
+          # Fail-soft like the star count: browsers still load the stats live; only crawlers and
+          # LLM fetchers, which run no JS, see no numbers until the next deploy.
+          grep -q 'data-stats-snapshot=' out/index.html || echo "::warning::Platform stats were not baked into the landing page (reason in the build log) - crawlers and LLM fetchers see no numbers until the next deploy"
 
       # One archive of the exact bytes that get uploaded, so the attestation has a single subject.
       - name: Package export

rules/analyze/ANALYZE-DEV-013.json

@@ -0,0 +1,118 @@
+{
+  "$schema": "../schema/analyze-rule.schema.json",
+  "ruleId": "ANALYZE-DEV-013",
+  "title": "OOBE Quality Update Failed",
+  "description": "Detects that the Windows quality update page at the end of OOBE (Enrollment Status Page setting \"Install Windows quality updates\") reported a failed download or install and recorded no successful install afterwards — the page's own failure names on the oobe_update_page events. Setup usually continues, so the failure is otherwise invisible: the device finishes OOBE without the monthly security update. An OS build change across a restart (os_build_changed) vetoes the finding, and so does the agent's names_capped marker — once the page's event names were capped, a missing success name proves nothing. A downloadInstallFailureHelper entry alone is no failure: updates that installed fine log it too.",
+  "severity": "warning",
+  "category": "device",
+  "version": "1.0.0",
+  "enabled": true,
+  "evaluateOn": [
+    "enrollment_end"
+  ],
+  "trigger": "single",
+  "baseConfidence": 75,
+  "confidenceThreshold": 60,
+  "conditions": [
+    {
+      "signal": "update_failure",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "in",
+      "value": "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError,SdxWebAppCloudNDUP_processStatusChangeFromHandler_installFailedError,ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure",
+      "required": true
+    },
+    {
+      "signal": "no_install_success",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "name",
+      "filterOperator": "regex",
+      "filterValue": "installSucceededRebootRequired|commitExpeditionDownloadInstallAsyncSucceeded",
+      "required": true
+    },
+    {
+      "signal": "os_build_unchanged",
+      "source": "event_type",
+      "eventType": "os_build_changed",
+      "operator": "not_exists",
+      "value": "",
+      "required": true
+    },
+    {
+      "signal": "page_names_complete",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "cxhEvent",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "cxhEvent",
+      "filterOperator": "equals",
+      "filterValue": "names_capped",
+      "required": true
+    },
+    {
+      "signal": "update_page_failed",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "result",
+      "operator": "equals",
+      "value": "fail",
+      "filterField": "page",
+      "filterOperator": "equals",
+      "filterValue": "OobeNDUP",
+      "required": false
+    },
+    {
+      "signal": "update_skipped",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "regex",
+      "value": "SkipDownloadInstallButtonClicked$",
+      "required": false
+    }
+  ],
+  "confidenceFactors": [
+    {
+      "signal": "update_page_failed",
+      "condition": "exists",
+      "weight": 10
+    }
+  ],
+  "explanation": "The Windows quality update page at the end of OOBE reported `{{update_failure}}`, and no successful install was recorded afterwards. When the download or install of the update fails, the page gives up and setup continues, so the enrollment itself can still succeed — but the device most likely finished OOBE without the monthly security update and installs it only later, through the Windows Update policy that applies after enrollment. Selecting Skip on the page after the failure leads to the same result.",
+  "remediation": [
+    {
+      "title": "Find out why the update failed",
+      "steps": [
+        "Open the oobe_update_page events around the failure in the session timeline: the download progress before it shows how far the download got, and a Skip after it shows that someone chose to continue.",
+        "Check the network path the device uses during OOBE for Windows Update and Delivery Optimization: proxy, TLS inspection and firewall rules for the Windows Update endpoints.",
+        "Compare with other devices: the same failure on many devices of one site points at the network path, on one model at the device, and across the fleet at the update itself."
+      ]
+    },
+    {
+      "title": "Make sure the device gets the update",
+      "steps": [
+        "Verify the device's patch level after enrollment; the update ring assigned to the device installs the missing monthly security update on its normal schedule.",
+        "Where the OOBE quality update keeps failing for one network or device group, decide per Enrollment Status Page profile whether \"Install Windows quality updates\" should stay on."
+      ]
+    }
+  ],
+  "relatedDocs": [
+    {
+      "title": "Microsoft Learn: Install Windows quality updates during OOBE (Enrollment Status Page)",
+      "url": "https://learn.microsoft.com/en-us/intune/device-enrollment/windows/setup-status-page#windows-monthly-security-update-release-details"
+    }
+  ],
+  "markSessionAsFailedDefault": false,
+  "tags": [
+    "device",
+    "windows-update",
+    "oobe",
+    "quality-update"
+  ]
+}

rules/analyze/ANALYZE-DEV-014.json

@@ -0,0 +1,119 @@
+{
+  "$schema": "../schema/analyze-rule.schema.json",
+  "ruleId": "ANALYZE-DEV-014",
+  "title": "OOBE Quality Update Not Offered After an Earlier Failure",
+  "description": "Detects that the Windows quality update page at the end of OOBE found no update to install although the device is out of date, on a device whose update page counts an earlier failed download or install (oobe_update_page: NDUPDownloadInstallPreviousFailureCount above 0, osUpdatesWithNDUPPI false, getDaysOutOfDateSucceeded above 0). No failure and no install success are recorded in this session — a failure in this session is ANALYZE-DEV-013 — and the agent's names_capped marker vetoes the finding, because a missing name proves nothing once the page's names were capped. The device finishes OOBE without the monthly security update.",
+  "severity": "warning",
+  "category": "device",
+  "version": "1.0.0",
+  "enabled": true,
+  "evaluateOn": [
+    "enrollment_end"
+  ],
+  "trigger": "single",
+  "baseConfidence": 75,
+  "confidenceThreshold": 60,
+  "conditions": [
+    {
+      "signal": "previous_failures",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "value",
+      "operator": "gt",
+      "value": "0",
+      "filterField": "name",
+      "filterOperator": "equals",
+      "filterValue": "SdxWebAppCloudNDUP_initialize_NDUPDownloadInstallPreviousFailureCount",
+      "required": true
+    },
+    {
+      "signal": "nothing_offered",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "value",
+      "operator": "equals",
+      "value": "false",
+      "filterField": "name",
+      "filterOperator": "equals",
+      "filterValue": "SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI",
+      "required": true
+    },
+    {
+      "signal": "days_out_of_date",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "value",
+      "operator": "gt",
+      "value": "0",
+      "filterField": "name",
+      "filterOperator": "equals",
+      "filterValue": "ExpeditedUpdate_getDaysOutOfDateSucceeded",
+      "required": true
+    },
+    {
+      "signal": "no_update_failure",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "name",
+      "filterOperator": "in",
+      "filterValue": "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError,SdxWebAppCloudNDUP_processStatusChangeFromHandler_installFailedError,ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure",
+      "required": true
+    },
+    {
+      "signal": "no_install_success",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "name",
+      "filterOperator": "regex",
+      "filterValue": "installSucceededRebootRequired|commitExpeditionDownloadInstallAsyncSucceeded",
+      "required": true
+    },
+    {
+      "signal": "page_names_complete",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "cxhEvent",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "cxhEvent",
+      "filterOperator": "equals",
+      "filterValue": "names_capped",
+      "required": true
+    }
+  ],
+  "explanation": "The Windows quality update page at the end of OOBE checked for updates and found none to install, although Windows reports the device as {{days_out_of_date}} days out of date. The page's failure counter for this device stands at {{previous_failures}}: an earlier download or install of an OOBE quality update on this device failed. The device finished OOBE without the monthly security update and installs it only later, through the Windows Update policy that applies after enrollment.",
+  "remediation": [
+    {
+      "title": "Check the earlier attempt",
+      "steps": [
+        "Look at the device's earlier enrollment sessions — the failed attempt and its ANALYZE-DEV-013 finding are usually there.",
+        "Verify the device's patch level after enrollment; the update ring assigned to the device installs the missing monthly security update on its normal schedule."
+      ]
+    },
+    {
+      "title": "Reduce how far behind devices start",
+      "steps": [
+        "Devices that start OOBE many months behind need a long update during setup; a current OS image or factory build shortens it and gives a failed attempt less to repeat."
+      ]
+    }
+  ],
+  "relatedDocs": [
+    {
+      "title": "Microsoft Learn: Install Windows quality updates during OOBE (Enrollment Status Page)",
+      "url": "https://learn.microsoft.com/en-us/intune/device-enrollment/windows/setup-status-page#windows-monthly-security-update-release-details"
+    }
+  ],
+  "markSessionAsFailedDefault": false,
+  "tags": [
+    "device",
+    "windows-update",
+    "oobe",
+    "quality-update"
+  ]
+}

rules/analyze/ANALYZE-DEV-015.json

@@ -0,0 +1,117 @@
+{
+  "$schema": "../schema/analyze-rule.schema.json",
+  "ruleId": "ANALYZE-DEV-015",
+  "title": "OOBE Update Check Ended Without a Result",
+  "description": "Detects that the Windows quality update page at the end of OOBE started its Windows Update scan but ended without a scan result (oobe_update_page: startWUScanStartedSuccedded, an OobeNDUP stop and no ExpeditedUpdate_getUpdateResults name), on a device that is out of date and allowed to update. In the observed sessions the page ended two minutes after the scan started, on devices more than a year behind. The device finishes OOBE without the monthly security update. The agent's names_capped marker vetoes the finding: once the page's event names were capped, a missing scan result proves nothing.",
+  "severity": "warning",
+  "category": "device",
+  "version": "1.0.0",
+  "enabled": true,
+  "evaluateOn": [
+    "enrollment_end"
+  ],
+  "trigger": "single",
+  "baseConfidence": 75,
+  "confidenceThreshold": 60,
+  "conditions": [
+    {
+      "signal": "update_allowed",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "value",
+      "operator": "equals",
+      "value": "true",
+      "filterField": "name",
+      "filterOperator": "equals",
+      "filterValue": "ExpeditedUpdate_isNDUPAllowedByCSPSucceeded",
+      "required": true
+    },
+    {
+      "signal": "scan_started",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "equals",
+      "value": "ExpeditedUpdate_startWUScanStartedSuccedded",
+      "required": true
+    },
+    {
+      "signal": "no_scan_result",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "name",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "name",
+      "filterOperator": "regex",
+      "filterValue": "^ExpeditedUpdate_getUpdateResults",
+      "required": true
+    },
+    {
+      "signal": "update_page_ended",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "cxhEvent",
+      "operator": "equals",
+      "value": "page_stopped",
+      "filterField": "page",
+      "filterOperator": "equals",
+      "filterValue": "OobeNDUP",
+      "required": true
+    },
+    {
+      "signal": "days_out_of_date",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "value",
+      "operator": "gt",
+      "value": "0",
+      "filterField": "name",
+      "filterOperator": "equals",
+      "filterValue": "ExpeditedUpdate_getDaysOutOfDateSucceeded",
+      "required": true
+    },
+    {
+      "signal": "page_names_complete",
+      "source": "event_data",
+      "eventType": "oobe_update_page",
+      "dataField": "cxhEvent",
+      "operator": "not_exists",
+      "value": "",
+      "filterField": "cxhEvent",
+      "filterOperator": "equals",
+      "filterValue": "names_capped",
+      "required": true
+    }
+  ],
+  "explanation": "The Windows quality update page at the end of OOBE started a Windows Update scan, but no scan result arrived before the page ended. The device is {{days_out_of_date}} days out of date, so an update was due — the device finished OOBE without the monthly security update and installs it only later, through the Windows Update policy that applies after enrollment. The page waits only a short time for the scan (two minutes in the observed sessions): a scan that takes longer, or cannot reach Windows Update, ends the page without an update.",
+  "remediation": [
+    {
+      "title": "Check the path to Windows Update during OOBE",
+      "steps": [
+        "Verify that devices in OOBE reach the Windows Update service: proxy, TLS inspection and firewall rules for the Windows Update endpoints.",
+        "Check whether an update policy applied during the Enrollment Status Page points the scan at another source, such as WSUS."
+      ]
+    },
+    {
+      "title": "Shorten the scan",
+      "steps": [
+        "Devices far behind scan longer; a current OS image or factory build keeps the OOBE scan short.",
+        "Verify the device's patch level after enrollment; the update ring assigned to the device installs the missing monthly security update on its normal schedule."
+      ]
+    }
+  ],
+  "relatedDocs": [
+    {
+      "title": "Microsoft Learn: Install Windows quality updates during OOBE (Enrollment Status Page)",
+      "url": "https://learn.microsoft.com/en-us/intune/device-enrollment/windows/setup-status-page#windows-monthly-security-update-release-details"
+    }
+  ],
+  "markSessionAsFailedDefault": false,
+  "tags": [
+    "device",
+    "windows-update",
+    "oobe",
+    "quality-update"
+  ]
+}

rules/dist/analyze-rules.json

@@ -1930,6 +1930,357 @@
         "environment"
       ]
     },
+    {
+      "ruleId": "ANALYZE-DEV-013",
+      "title": "OOBE Quality Update Failed",
+      "description": "Detects that the Windows quality update page at the end of OOBE (Enrollment Status Page setting \"Install Windows quality updates\") reported a failed download or install and recorded no successful install afterwards — the page's own failure names on the oobe_update_page events. Setup usually continues, so the failure is otherwise invisible: the device finishes OOBE without the monthly security update. An OS build change across a restart (os_build_changed) vetoes the finding, and so does the agent's names_capped marker — once the page's event names were capped, a missing success name proves nothing. A downloadInstallFailureHelper entry alone is no failure: updates that installed fine log it too.",
+      "severity": "warning",
+      "category": "device",
+      "version": "1.0.0",
+      "enabled": true,
+      "evaluateOn": [
+        "enrollment_end"
+      ],
+      "trigger": "single",
+      "baseConfidence": 75,
+      "confidenceThreshold": 60,
+      "conditions": [
+        {
+          "signal": "update_failure",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "in",
+          "value": "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError,SdxWebAppCloudNDUP_processStatusChangeFromHandler_installFailedError,ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure",
+          "required": true
+        },
+        {
+          "signal": "no_install_success",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "name",
+          "filterOperator": "regex",
+          "filterValue": "installSucceededRebootRequired|commitExpeditionDownloadInstallAsyncSucceeded",
+          "required": true
+        },
+        {
+          "signal": "os_build_unchanged",
+          "source": "event_type",
+          "eventType": "os_build_changed",
+          "operator": "not_exists",
+          "value": "",
+          "required": true
+        },
+        {
+          "signal": "page_names_complete",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "cxhEvent",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "cxhEvent",
+          "filterOperator": "equals",
+          "filterValue": "names_capped",
+          "required": true
+        },
+        {
+          "signal": "update_page_failed",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "result",
+          "operator": "equals",
+          "value": "fail",
+          "filterField": "page",
+          "filterOperator": "equals",
+          "filterValue": "OobeNDUP",
+          "required": false
+        },
+        {
+          "signal": "update_skipped",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "regex",
+          "value": "SkipDownloadInstallButtonClicked$",
+          "required": false
+        }
+      ],
+      "confidenceFactors": [
+        {
+          "signal": "update_page_failed",
+          "condition": "exists",
+          "weight": 10
+        }
+      ],
+      "explanation": "The Windows quality update page at the end of OOBE reported `{{update_failure}}`, and no successful install was recorded afterwards. When the download or install of the update fails, the page gives up and setup continues, so the enrollment itself can still succeed — but the device most likely finished OOBE without the monthly security update and installs it only later, through the Windows Update policy that applies after enrollment. Selecting Skip on the page after the failure leads to the same result.",
+      "remediation": [
+        {
+          "title": "Find out why the update failed",
+          "steps": [
+            "Open the oobe_update_page events around the failure in the session timeline: the download progress before it shows how far the download got, and a Skip after it shows that someone chose to continue.",
+            "Check the network path the device uses during OOBE for Windows Update and Delivery Optimization: proxy, TLS inspection and firewall rules for the Windows Update endpoints.",
+            "Compare with other devices: the same failure on many devices of one site points at the network path, on one model at the device, and across the fleet at the update itself."
+          ]
+        },
+        {
+          "title": "Make sure the device gets the update",
+          "steps": [
+            "Verify the device's patch level after enrollment; the update ring assigned to the device installs the missing monthly security update on its normal schedule.",
+            "Where the OOBE quality update keeps failing for one network or device group, decide per Enrollment Status Page profile whether \"Install Windows quality updates\" should stay on."
+          ]
+        }
+      ],
+      "relatedDocs": [
+        {
+          "title": "Microsoft Learn: Install Windows quality updates during OOBE (Enrollment Status Page)",
+          "url": "https://learn.microsoft.com/en-us/intune/device-enrollment/windows/setup-status-page#windows-monthly-security-update-release-details"
+        }
+      ],
+      "markSessionAsFailedDefault": false,
+      "tags": [
+        "device",
+        "windows-update",
+        "oobe",
+        "quality-update"
+      ]
+    },
+    {
+      "ruleId": "ANALYZE-DEV-014",
+      "title": "OOBE Quality Update Not Offered After an Earlier Failure",
+      "description": "Detects that the Windows quality update page at the end of OOBE found no update to install although the device is out of date, on a device whose update page counts an earlier failed download or install (oobe_update_page: NDUPDownloadInstallPreviousFailureCount above 0, osUpdatesWithNDUPPI false, getDaysOutOfDateSucceeded above 0). No failure and no install success are recorded in this session — a failure in this session is ANALYZE-DEV-013 — and the agent's names_capped marker vetoes the finding, because a missing name proves nothing once the page's names were capped. The device finishes OOBE without the monthly security update.",
+      "severity": "warning",
+      "category": "device",
+      "version": "1.0.0",
+      "enabled": true,
+      "evaluateOn": [
+        "enrollment_end"
+      ],
+      "trigger": "single",
+      "baseConfidence": 75,
+      "confidenceThreshold": 60,
+      "conditions": [
+        {
+          "signal": "previous_failures",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "value",
+          "operator": "gt",
+          "value": "0",
+          "filterField": "name",
+          "filterOperator": "equals",
+          "filterValue": "SdxWebAppCloudNDUP_initialize_NDUPDownloadInstallPreviousFailureCount",
+          "required": true
+        },
+        {
+          "signal": "nothing_offered",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "value",
+          "operator": "equals",
+          "value": "false",
+          "filterField": "name",
+          "filterOperator": "equals",
+          "filterValue": "SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI",
+          "required": true
+        },
+        {
+          "signal": "days_out_of_date",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "value",
+          "operator": "gt",
+          "value": "0",
+          "filterField": "name",
+          "filterOperator": "equals",
+          "filterValue": "ExpeditedUpdate_getDaysOutOfDateSucceeded",
+          "required": true
+        },
+        {
+          "signal": "no_update_failure",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "name",
+          "filterOperator": "in",
+          "filterValue": "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError,SdxWebAppCloudNDUP_processStatusChangeFromHandler_installFailedError,ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure",
+          "required": true
+        },
+        {
+          "signal": "no_install_success",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "name",
+          "filterOperator": "regex",
+          "filterValue": "installSucceededRebootRequired|commitExpeditionDownloadInstallAsyncSucceeded",
+          "required": true
+        },
+        {
+          "signal": "page_names_complete",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "cxhEvent",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "cxhEvent",
+          "filterOperator": "equals",
+          "filterValue": "names_capped",
+          "required": true
+        }
+      ],
+      "explanation": "The Windows quality update page at the end of OOBE checked for updates and found none to install, although Windows reports the device as {{days_out_of_date}} days out of date. The page's failure counter for this device stands at {{previous_failures}}: an earlier download or install of an OOBE quality update on this device failed. The device finished OOBE without the monthly security update and installs it only later, through the Windows Update policy that applies after enrollment.",
+      "remediation": [
+        {
+          "title": "Check the earlier attempt",
+          "steps": [
+            "Look at the device's earlier enrollment sessions — the failed attempt and its ANALYZE-DEV-013 finding are usually there.",
+            "Verify the device's patch level after enrollment; the update ring assigned to the device installs the missing monthly security update on its normal schedule."
+          ]
+        },
+        {
+          "title": "Reduce how far behind devices start",
+          "steps": [
+            "Devices that start OOBE many months behind need a long update during setup; a current OS image or factory build shortens it and gives a failed attempt less to repeat."
+          ]
+        }
+      ],
+      "relatedDocs": [
+        {
+          "title": "Microsoft Learn: Install Windows quality updates during OOBE (Enrollment Status Page)",
+          "url": "https://learn.microsoft.com/en-us/intune/device-enrollment/windows/setup-status-page#windows-monthly-security-update-release-details"
+        }
+      ],
+      "markSessionAsFailedDefault": false,
+      "tags": [
+        "device",
+        "windows-update",
+        "oobe",
+        "quality-update"
+      ]
+    },
+    {
+      "ruleId": "ANALYZE-DEV-015",
+      "title": "OOBE Update Check Ended Without a Result",
+      "description": "Detects that the Windows quality update page at the end of OOBE started its Windows Update scan but ended without a scan result (oobe_update_page: startWUScanStartedSuccedded, an OobeNDUP stop and no ExpeditedUpdate_getUpdateResults name), on a device that is out of date and allowed to update. In the observed sessions the page ended two minutes after the scan started, on devices more than a year behind. The device finishes OOBE without the monthly security update. The agent's names_capped marker vetoes the finding: once the page's event names were capped, a missing scan result proves nothing.",
+      "severity": "warning",
+      "category": "device",
+      "version": "1.0.0",
+      "enabled": true,
+      "evaluateOn": [
+        "enrollment_end"
+      ],
+      "trigger": "single",
+      "baseConfidence": 75,
+      "confidenceThreshold": 60,
+      "conditions": [
+        {
+          "signal": "update_allowed",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "value",
+          "operator": "equals",
+          "value": "true",
+          "filterField": "name",
+          "filterOperator": "equals",
+          "filterValue": "ExpeditedUpdate_isNDUPAllowedByCSPSucceeded",
+          "required": true
+        },
+        {
+          "signal": "scan_started",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "equals",
+          "value": "ExpeditedUpdate_startWUScanStartedSuccedded",
+          "required": true
+        },
+        {
+          "signal": "no_scan_result",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "name",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "name",
+          "filterOperator": "regex",
+          "filterValue": "^ExpeditedUpdate_getUpdateResults",
+          "required": true
+        },
+        {
+          "signal": "update_page_ended",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "cxhEvent",
+          "operator": "equals",
+          "value": "page_stopped",
+          "filterField": "page",
+          "filterOperator": "equals",
+          "filterValue": "OobeNDUP",
+          "required": true
+        },
+        {
+          "signal": "days_out_of_date",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "value",
+          "operator": "gt",
+          "value": "0",
+          "filterField": "name",
+          "filterOperator": "equals",
+          "filterValue": "ExpeditedUpdate_getDaysOutOfDateSucceeded",
+          "required": true
+        },
+        {
+          "signal": "page_names_complete",
+          "source": "event_data",
+          "eventType": "oobe_update_page",
+          "dataField": "cxhEvent",
+          "operator": "not_exists",
+          "value": "",
+          "filterField": "cxhEvent",
+          "filterOperator": "equals",
+          "filterValue": "names_capped",
+          "required": true
+        }
+      ],
+      "explanation": "The Windows quality update page at the end of OOBE started a Windows Update scan, but no scan result arrived before the page ended. The device is {{days_out_of_date}} days out of date, so an update was due — the device finished OOBE without the monthly security update and installs it only later, through the Windows Update policy that applies after enrollment. The page waits only a short time for the scan (two minutes in the observed sessions): a scan that takes longer, or cannot reach Windows Update, ends the page without an update.",
+      "remediation": [
+        {
+          "title": "Check the path to Windows Update during OOBE",
+          "steps": [
+            "Verify that devices in OOBE reach the Windows Update service: proxy, TLS inspection and firewall rules for the Windows Update endpoints.",
+            "Check whether an update policy applied during the Enrollment Status Page points the scan at another source, such as WSUS."
+          ]
+        },
+        {
+          "title": "Shorten the scan",
+          "steps": [
+            "Devices far behind scan longer; a current OS image or factory build keeps the OOBE scan short.",
+            "Verify the device's patch level after enrollment; the update ring assigned to the device installs the missing monthly security update on its normal schedule."
+          ]
+        }
+      ],
+      "relatedDocs": [
+        {
+          "title": "Microsoft Learn: Install Windows quality updates during OOBE (Enrollment Status Page)",
+          "url": "https://learn.microsoft.com/en-us/intune/device-enrollment/windows/setup-status-page#windows-monthly-security-update-release-details"
+        }
+      ],
+      "markSessionAsFailedDefault": false,
+      "tags": [
+        "device",
+        "windows-update",
+        "oobe",
+        "quality-update"
+      ]
+    },
     {
       "ruleId": "ANALYZE-ENRL-001",
       "title": "Enrollment Failed",

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerHealthTests.cs

@@ -140,6 +140,22 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
             Assert.Equal(1, fired); // the persisted flag suppressed the second emission
         }
 
+        [Fact]
+        public void Registry_reconciliation_counters_survive_a_restart()
+        {
+            using var h = new Harness();
+            h.Tracker.ScriptRuns.CountVerified();
+            h.Tracker.ScriptRuns.CountVerified();
+            h.Tracker.ScriptRuns.CountCorrected();
+            h.Tracker.SaveStateForTest();
+
+            h.Restart();
+
+            var health = h.Tracker.GetHealthSnapshot();
+            Assert.Equal(2, health.PlatformOutputVerified);
+            Assert.Equal(1, health.PlatformOutputCorrected);
+        }
+
         [Fact]
         public async Task Handler_time_does_not_count_against_the_line_budget()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerOverwriteRewindTests.RetryPairing.cs

@@ -0,0 +1,336 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
+{
+    /// <summary>
+    /// B-96m: IME re-runs a failed platform script on later check-ins, so AgentExecutor.log can hold several runs of one
+    /// policy before the tracker has read IME's result of the first — always on the agent's first pass (the agent starts
+    /// mid-enrollment and reads all of AgentExecutor.log before IntuneManagementExtension.log), after a restart, and
+    /// whenever a result line surfaces late. With one slot per policy the second executor start reused the first run's
+    /// slot and its end block overwrote the first one: the first IME result went out with the LAST run's exit code and
+    /// output (session eff1b413: the bootstrap script "Failed (exit 0)" with the stdout of its successful retry), every
+    /// later result without an end block. These tests pin one run per executor start, each IME result paired with the
+    /// run of its policy that started last before it, each run carrying its own end block.
+    /// </summary>
+    public sealed partial class ImeLogTrackerOverwriteRewindTests
+    {
+        private const string RetryPolicyId = "4c2d8e1a-7b3f-4a9e-8d21-6f0b5c3e9a74";
+        private const string RetryUser = "00000000-0000-0000-0000-000000000000";
+
+        private static string ImeEntryAt(string time, string message)
+            => $"<![LOG[{message}]LOG]!><time=\"{time}\" date=\"9-10-2026\" component=\"IntuneManagementExtension\" context=\"\" type=\"1\" thread=\"12\" file=\"\">\r\n";
+
+        /// <summary>One executor run's start block: banner, the platform argument line, paths, launch.</summary>
+        private static string RunStart(string time, string pid, string policyId = RetryPolicyId, string userId = RetryUser)
+        {
+            var path = $@"{ImeDir}\Policies\Scripts\{userId}_{policyId}.ps1";
+            var results = $@"{ImeDir}\Policies\Results\{userId}_{policyId}";
+            return ExecutorBanner(time)
+                + EntryAt(time, $"Adding argument powershell with value {path} to the named argument list.")
+                + EntryAt(time, "Powershell option gets invoked")
+                + EntryAt(time, path)
+                + EntryAt(time, results + ".output")
+                + EntryAt(time, results + ".error")
+                + EntryAt(time, results + ".timeout")
+                + ExecutorLaunch(time, path, pid);
+        }
+
+        /// <summary>
+        /// One executor run's end block in AgentExecutor's order. "error from script =" logs the stderr buffer before the
+        /// output readers finished (<paramref name="stderrSnapshot"/>); "write output done" logs the final texts, the
+        /// error part being exactly the error file IME judges.
+        /// </summary>
+        private static string RunEnd(string time, int exitCode, string stdout, string stderr, string? stderrSnapshot = null)
+            => EntryAt(time, $"Powershell exit code is {exitCode}")
+            + EntryAt(time, $"length of out={stdout.Length}")
+            + EntryAt(time, $"length of error={stderr.Length}")
+            + EntryAt(time, "error from script =" + (stderrSnapshot ?? stderr))
+            + EntryAt(time, exitCode == 0 ? "Powershell script is successfully executed." : "Powershell script is failed to execute")
+            + EntryAt(time, $"write output done. output = {stdout}, error = {stderr}")
+            + EntryAt(time, "Revert Wow64FsRedirection")
+            + EntryAt(time, "Agent executor completed.");
+
+        private static string ImeRunStart(string time, string policyId = RetryPolicyId, string userId = RetryUser)
+            => ImeEntryAt(time, $@"Script file {ImeDir}\Policies\Scripts\{userId}_{policyId}.ps1 is generated.");
+
+        private static string ImeRunResult(string time, string result, string policyId = RetryPolicyId, string userId = RetryUser)
+            => ImeEntryAt(time, $"[PowerShell] User Id = {userId}, Policy id = {policyId}, policy result = {result}");
+
+        private static void AppendImeLog(Harness h, string text)
+            => File.AppendAllText(Path.Combine(Path.GetDirectoryName(h.LogPath)!, "IntuneManagementExtension.log"), text, new UTF8Encoding(false));
+
+        /// <summary>Result | exit | stdout | stderr — readable in an assertion failure; "-" no exit code, "~" never read.</summary>
+        private static string Shape(ScriptExecutionState s)
+            => $"{s.Result}|{(s.ExitCode.HasValue ? s.ExitCode.Value.ToString() : "-")}|{s.Stdout ?? "~"}|{s.Stderr ?? "~"}";
+
+        /// <summary>
+        /// Two poll passes as the agent runs them (read the files, then the flushes), the second past the result hold:
+        /// a result missing its end block goes out by then.
+        /// </summary>
+        private static async Task PassAndSettle(Harness h)
+        {
+            await h.Tracker.RunPollPassAsync(default);
+            h.Now = h.Now.AddSeconds(6);
+            await h.Tracker.RunPollPassAsync(default);
+        }
+
+        [Fact]
+        public async Task First_pass_pairs_each_ime_result_with_the_end_block_of_its_own_run()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            // IME's first run and two retries on later check-ins, all written before the agent started.
+            h.Append(RunStart("12:00:10.0000000", "1001") + RunEnd("12:00:12.0000000", 1, "", "Run A failed")
+                + RunStart("12:10:10.0000000", "1002") + RunEnd("12:10:12.0000000", 1, "Run B output", "")
+                + RunStart("12:20:10.0000000", "1003") + RunEnd("12:20:12.0000000", 0, "Run C output", ""));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Failed")
+                + ImeRunStart("12:10:08.0000000") + ImeRunResult("12:10:12.1000000", "Success")
+                + ImeRunStart("12:20:08.0000000") + ImeRunResult("12:20:12.1000000", "Success"));
+
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Failed|1||Run A failed", "Success|1|Run B output|", "Success|0|Run C output|" },
+                h.Completed.Select(Shape).ToArray());
+            Assert.All(h.Completed, s => Assert.Equal("ime_policy_result", s.ResultSource));
+            Assert.True(h.Completed[0].StartedAtUtc < h.Completed[1].StartedAtUtc && h.Completed[1].StartedAtUtc < h.Completed[2].StartedAtUtc);
+            Assert.Equal(3, h.Completed.Select(s => s.RunId).Distinct().Count());
+        }
+
+        [Fact]
+        public async Task Retry_of_the_bootstrap_script_never_lends_its_success_output_to_the_failed_first_attempt()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "2001") + RunEnd("12:00:20.0000000", 1, "attempt 1: download failed", "Invoke-WebRequest : The remote name could not be resolved")
+                + RunStart("12:10:10.0000000", "2002") + RunEnd("12:10:20.0000000", 0, "===== Bootstrap Completed Successfully =====", ""));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:20.1000000", "Failed")
+                + ImeRunStart("12:10:08.0000000") + ImeRunResult("12:10:20.1000000", "Success"));
+
+            await PassAndSettle(h);
+
+            Assert.Equal(new[]
+            {
+                "Failed|1|attempt 1: download failed|Invoke-WebRequest : The remote name could not be resolved",
+                "Success|0|===== Bootstrap Completed Successfully =====|",
+            }, h.Completed.Select(Shape).ToArray());
+        }
+
+        [Fact]
+        public async Task Run_killed_at_the_timeout_reports_failed_without_the_next_runs_end_block()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            // IME killed the first executor after 1800 s: its start block is all AgentExecutor.log holds of it.
+            h.Append(RunStart("12:00:10.0000000", "3001")
+                + RunStart("12:40:10.0000000", "3002") + RunEnd("12:40:12.0000000", 0, "Run B output", ""));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:30:10.5000000", "Failed")
+                + ImeRunStart("12:40:08.0000000") + ImeRunResult("12:40:12.1000000", "Success"));
+
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Failed|-|~|~", "Success|0|Run B output|" }, h.Completed.Select(Shape).ToArray());
+        }
+
+        [Fact]
+        public async Task Run_whose_result_never_surfaced_falls_back_on_imes_rule_before_the_next_run()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "4001") + RunEnd("12:00:12.0000000", 0, "Run A output", "Run A wrote an error")
+                + RunStart("12:10:10.0000000", "4002") + RunEnd("12:10:12.0000000", 0, "Run B output", ""));
+            // Run A's result line was lost; run B's is there.
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunStart("12:10:08.0000000") + ImeRunResult("12:10:12.1000000", "Success"));
+
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Failed|0|Run A output|Run A wrote an error", "Success|0|Run B output|" }, h.Completed.Select(Shape).ToArray());
+            Assert.Equal(new[] { "agentexecutor_fallback", "ime_policy_result" }, h.Completed.Select(s => s.ResultSource).ToArray());
+        }
+
+        [Fact]
+        public async Task Run_in_flight_survives_the_emit_of_the_run_before_it()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "5001") + RunEnd("12:00:12.0000000", 0, "Run A output", "")
+                + RunStart("12:10:10.0000000", "5002"));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Success") + ImeRunStart("12:10:08.0000000"));
+            await PassAndSettle(h);
+            h.Now = h.Now.AddSeconds(30);
+            await h.Pass();
+
+            // Run B ends minutes later.
+            h.Append(RunEnd("12:10:40.0000000", 0, "Run B output", ""));
+            AppendImeLog(h, ImeRunResult("12:10:40.1000000", "Success"));
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Success|0|Run A output|", "Success|0|Run B output|" }, h.Completed.Select(Shape).ToArray());
+        }
+
+        [Fact]
+        public async Task Shutdown_between_the_two_logs_flushes_each_run_with_its_own_end_block()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "6001") + RunEnd("12:00:12.0000000", 1, "", "Run A failed")
+                + RunStart("12:10:10.0000000", "6002") + RunEnd("12:10:12.0000000", 0, "Run B output", ""));
+            // The pass is cancelled after AgentExecutor.log; the shutdown flush follows.
+            await h.Pass();
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now, force: true);
+
+            h.Restart();
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Failed")
+                + ImeRunStart("12:10:08.0000000") + ImeRunResult("12:10:12.1000000", "Success"));
+            await PassAndSettle(h);
+
+            // Each run went out with its own block and IME's verdict on it; the results read after the restart are
+            // the same runs and change nothing.
+            Assert.Equal(new[] { "Failed|1||Run A failed", "Success|0|Run B output|" }, h.Completed.Select(Shape).ToArray());
+            Assert.All(h.Completed, s => Assert.Equal("agentexecutor_fallback", s.ResultSource));
+        }
+
+        [Fact]
+        public async Task End_block_line_recovered_after_the_next_run_started_stays_with_its_own_run()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "7001"));
+            var exitLineAt = h.Length;
+            h.Append(RunEnd("12:00:12.0000000", 1, "", "Run A failed")
+                + RunStart("12:10:10.0000000", "7002") + RunEnd("12:10:12.0000000", 0, "Run B output", ""));
+            await h.Pass();
+
+            // A stale writer rewrites run A's exit line in place: the ledger check re-reads it behind run B's start.
+            h.Overwrite(exitLineAt, EntryAt("12:00:12.0000000", "Powershell exit code is 7"));
+            h.Tracker.RequestOverwriteCheckForTest();
+            h.Now = h.Now.AddSeconds(2);
+            await h.Pass();
+
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Failed")
+                + ImeRunStart("12:10:08.0000000") + ImeRunResult("12:10:12.1000000", "Success"));
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Failed|7||Run A failed", "Success|0|Run B output|" }, h.Completed.Select(Shape).ToArray());
+        }
+
+        [Fact]
+        public async Task Run_without_result_or_end_block_is_dropped_once_a_later_run_has_its_result()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "9001")
+                + RunStart("12:10:10.0000000", "9002") + RunEnd("12:10:12.0000000", 0, "Run B output", ""));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunStart("12:10:08.0000000") + ImeRunResult("12:10:12.1000000", "Success"));
+
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Success|0|Run B output|" }, h.Completed.Select(Shape).ToArray());
+            Assert.Equal(0, h.Tracker.ParkedPlatformScriptCountForTest);
+        }
+
+        [Fact]
+        public void Reading_the_same_executor_start_line_again_never_parks_its_run()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            var line = $@"Adding argument powershell with value {ImeDir}\Policies\Scripts\{RetryUser}_{RetryPolicyId}.ps1 to the named argument list.";
+            var at = T0.AddMinutes(-30);
+
+            h.Tracker.ProcessLogMessageForTest(line, at, "AgentExecutor.log");
+            h.Tracker.ProcessLogMessageForTest(line, at, "AgentExecutor.log");
+            Assert.Equal(0, h.Tracker.ParkedPlatformScriptCountForTest);
+
+            h.Tracker.ProcessLogMessageForTest(line, at.AddMinutes(10), "AgentExecutor.log");
+            Assert.Equal(1, h.Tracker.ParkedPlatformScriptCountForTest);
+        }
+
+        [Fact]
+        public async Task Run_without_end_block_keeps_waiting_for_its_result_across_a_shutdown()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "9101") + RunStart("12:40:10.0000000", "9102"));
+            await h.Pass();
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now, force: true);
+            Assert.Empty(h.Completed);
+
+            h.Restart();
+            Assert.Equal(1, h.Tracker.ParkedPlatformScriptCountForTest);
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:30:10.5000000", "Failed"));
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Failed|-|~|~" }, h.Completed.Select(Shape).ToArray());
+        }
+
+        [Fact]
+        public async Task Earlier_run_emitted_while_a_later_one_runs_never_takes_the_later_runs_register_entry()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "9201") + RunEnd("12:00:12.0000000", 1, "", "Run A failed")
+                + RunStart("12:10:10.0000000", "9202"));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Failed") + ImeRunStart("12:10:08.0000000"));
+            await PassAndSettle(h);
+            Assert.Single(h.Completed);
+
+            // A save of this key is the latest run's, and that one is still running.
+            h.Tracker.ScriptRuns.NotePassCompleted(h.Now);
+            Assert.Equal(PlatformRunClaim.Wait, h.Tracker.ScriptRuns.TryClaim(RetryUser, RetryPolicyId, h.Now.AddSeconds(-10), out _));
+
+            h.Append(RunEnd("12:10:40.0000000", 0, "Run B output", ""));
+            AppendImeLog(h, ImeRunResult("12:10:40.1000000", "Success"));
+            await PassAndSettle(h);
+            h.Tracker.ScriptRuns.NotePassCompleted(h.Now);
+
+            Assert.Equal(PlatformRunClaim.Claimed, h.Tracker.ScriptRuns.TryClaim(RetryUser, RetryPolicyId, h.Now.AddSeconds(-10), out var run));
+            Assert.Equal(h.Completed[1].RunId, run!.RunId);
+            Assert.Equal("Run B output", run.Stdout);
+        }
+
+        [Fact]
+        public async Task Run_of_another_user_keeps_its_own_register_entry_when_it_waited_for_its_result()
+        {
+            const string otherUser = "2b7e5c91-3d4a-4f80-b6e2-9a1c7d3f5e08";
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "9301") + RunEnd("12:00:12.0000000", 1, "", "Run A failed")
+                + RunStart("12:10:10.0000000", "9302", userId: otherUser));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Failed")
+                + ImeRunStart("12:10:08.0000000", userId: otherUser));
+            await PassAndSettle(h);
+            h.Tracker.ScriptRuns.NotePassCompleted(h.Now);
+
+            Assert.Equal(PlatformRunClaim.Claimed, h.Tracker.ScriptRuns.TryClaim(RetryUser, RetryPolicyId, h.Now.AddSeconds(-10), out var run));
+            Assert.Equal(h.Completed[0].RunId, run!.RunId);
+            Assert.Equal(PlatformRunClaim.Wait, h.Tracker.ScriptRuns.TryClaim(otherUser, RetryPolicyId, h.Now.AddSeconds(-10), out _));
+        }
+
+        [Fact]
+        public async Task Start_line_read_again_stays_a_late_line_after_an_earlier_run_of_another_user_went_out()
+        {
+            const string otherUser = "2b7e5c91-3d4a-4f80-b6e2-9a1c7d3f5e08";
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(RunStart("12:00:10.0000000", "9401") + RunEnd("12:00:12.0000000", 0, "Run A output", "")
+                + RunStart("12:10:10.0000000", "9402", userId: otherUser) + RunEnd("12:10:12.0000000", 0, "Run B output", ""));
+            // Run A's result surfaces after run B's (its line was hidden by a concurrent writer).
+            AppendImeLog(h, ImeRunResult("12:10:12.1000000", "Success", userId: otherUser) + ImeRunResult("12:00:12.1000000", "Success"));
+            await PassAndSettle(h);
+            Assert.Equal(new[] { "Success|0|Run B output|", "Success|0|Run A output|" }, h.Completed.Select(Shape).ToArray());
+
+            // Run B's executor start line read again (a rewind): a late line of the emitted run B, never a new run.
+            var started = 0;
+            h.Tracker.OnScriptStarted = _ => started++;
+            h.Tracker.ProcessLogMessageForTest(
+                $@"Adding argument powershell with value {ImeDir}\Policies\Scripts\{otherUser}_{RetryPolicyId}.ps1 to the named argument list.",
+                h.Completed[0].StartedAtUtc, "AgentExecutor.log");
+            Assert.Equal(0, started);
+        }
+
+        [Fact]
+        public async Task Final_stderr_of_the_end_block_replaces_the_early_snapshot_even_without_stdout()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            // The snapshot was taken before the error reader finished; IME judged the full error file.
+            h.Append(RunStart("12:00:10.0000000", "8001") + RunEnd("12:00:12.0000000", 0, "", "Remove-AppxPackage : Cannot process argument", stderrSnapshot: ""));
+            AppendImeLog(h, ImeRunStart("12:00:08.0000000") + ImeRunResult("12:00:12.1000000", "Failed"));
+
+            await PassAndSettle(h);
+
+            Assert.Equal(new[] { "Failed|0||Remove-AppxPackage : Cannot process argument" }, h.Completed.Select(Shape).ToArray());
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerOverwriteRewindTests.RewindFreshness.cs

@@ -0,0 +1,139 @@
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using AutopilotMonitor.Agent.V2.Core.SignalAdapters;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
+{
+    /// <summary>
+    /// Sessions d29e27e3 and 4377911b: a concurrent IME writer overwrote the result line of a platform script, and the
+    /// overwrite check recovered it one pass later. Recovered lines were never fresh, so they resolved in the agent's own
+    /// cached zone (+60) instead of anchoring themselves (+120): the end stamp landed an hour ahead of the clock and the
+    /// run duration was omitted. Bytes that read differently at a position than at the last look were written after that
+    /// look, so when the replaced bytes were confirmed seconds ago the new line's age is bounded like an appended line's —
+    /// these tests pin that it anchors itself then, and only then.
+    /// </summary>
+    public sealed partial class ImeLogTrackerOverwriteRewindTests
+    {
+        private static void AppendExecutorLog(Harness h, string text)
+            => File.AppendAllText(Path.Combine(Path.GetDirectoryName(h.LogPath)!, "AgentExecutor.log"), text, new UTF8Encoding(false));
+
+        /// <summary>An IME log entry with the byte length of <paramref name="sameLengthAs"/>: what a stale writer's line replaces exactly.</summary>
+        private static string FillerLike(string time, string sameLengthAs)
+        {
+            var bare = ImeEntryAt(time, "[Win32App] checking ");
+            Assert.True(sameLengthAs.Length > bare.Length);
+            return ImeEntryAt(time, "[Win32App] checking " + new string('x', sameLengthAs.Length - bare.Length));
+        }
+
+        /// <summary>
+        /// A platform run whose IME writer lives in +120 (local = UTC + 2 h; the harness clock is 19:30Z): both logs are
+        /// observed empty first, so what follows is read fresh. Returns the IME log position where the filler line sits.
+        /// </summary>
+        private static async Task<long> StartRunAndReadFiller(Harness h, string fillerTime, string resultEntry)
+        {
+            h.Append(string.Empty);
+            AppendExecutorLog(h, string.Empty);
+            await h.Tracker.RunPollPassAsync(default);
+
+            AppendExecutorLog(h, RunStart("21:29:50.0000000", "1001"));
+            h.Append(ImeRunStart("21:29:48.0000000"));
+            await h.Tracker.RunPollPassAsync(default);
+
+            // Another IME writer appends a line; the tracker reads it.
+            var at = h.Length;
+            h.Append(FillerLike(fillerTime, resultEntry));
+            h.Now = h.Now.AddSeconds(1);
+            await h.Tracker.RunPollPassAsync(default);
+            return at;
+        }
+
+        [Fact]
+        public async Task Result_line_recovered_seconds_after_its_bytes_were_read_anchors_itself_like_a_fresh_line()
+        {
+            using var h = new Harness("IntuneManagementExtension.log", ScriptPatterns());
+            var result = ImeRunResult("21:30:01.1000000", "Success");
+            var at = await StartRunAndReadFiller(h, "21:30:00.5000000", result);
+
+            // The script ends: its end block, then the stale IME service writes the result over the filler.
+            AppendExecutorLog(h, RunEnd("21:30:01.0000000", 0, "done", ""));
+            h.Overwrite(at, result);
+            h.Now = h.Now.AddSeconds(1);
+            await PassAndSettle(h);
+
+            Assert.Equal(1, h.Health.OverwriteRewinds);
+            var script = Assert.Single(h.Completed);
+            Assert.Equal(CmTraceOffsetOrigin.LineAnchored, script.ResultProvenance!.Origin);
+            Assert.Equal(120, script.ResultProvenance.OffsetMinutes);
+            Assert.Equal(ImeLogTrackerAdapter.DurationPairVerdict.Verified, ImeLogTrackerAdapter.JudgeDurationPair(
+                script.StartedAtProvenance, script.ResultProvenance, false, script.ResultObservedAtUtc!.Value - script.StartedAtUtc!.Value, out _));
+        }
+
+        [Fact]
+        public async Task Verification_passes_keep_the_replaced_bytes_current_for_a_script_that_runs_longer()
+        {
+            using var h = new Harness("IntuneManagementExtension.log", ScriptPatterns());
+            var result = ImeRunResult("21:30:41.1000000", "Success");
+            var at = await StartRunAndReadFiller(h, "21:30:00.5000000", result);
+
+            // The script runs 40 s; the cadence check verifies the ledger every 10 s while the run is in flight.
+            for (var i = 0; i < 4; i++)
+            {
+                h.Now = h.Now.AddSeconds(10);
+                await h.Tracker.RunPollPassAsync(default);
+            }
+
+            AppendExecutorLog(h, RunEnd("21:30:41.0000000", 0, "done", ""));
+            h.Overwrite(at, result);
+            h.Now = h.Now.AddSeconds(1);
+            await PassAndSettle(h);
+
+            var script = Assert.Single(h.Completed);
+            Assert.Equal(CmTraceOffsetOrigin.LineAnchored, script.ResultProvenance!.Origin);
+            Assert.Equal(120, script.ResultProvenance.OffsetMinutes);
+        }
+
+        [Fact]
+        public async Task Overwrite_does_not_move_the_files_measured_writer_offset()
+        {
+            using var h = new Harness("IntuneManagementExtension.log", ScriptPatterns());
+            var result = ImeRunResult("21:30:01.1000000", "Success");
+            var at = await StartRunAndReadFiller(h, "21:30:00.5000000", result);
+            Assert.True(h.Tracker.OffsetCalibrator.TryGetOffset("IntuneManagementExtension.log", out var before));
+
+            AppendExecutorLog(h, RunEnd("21:30:01.0000000", 0, "done", ""));
+            h.Overwrite(at, result);
+            h.Now = h.Now.AddSeconds(1);
+            await PassAndSettle(h);
+
+            Assert.True(h.Tracker.OffsetCalibrator.TryGetOffset("IntuneManagementExtension.log", out var after));
+            Assert.Equal(before, after);
+        }
+
+        [Theory]
+        // Replaced bytes confirmed 1 s / 30 s ago: written since, age bounded like an appended line's.
+        [InlineData(true, true, 1, true)]
+        [InlineData(true, true, 30, true)]
+        // Confirmed longer ago: the new bytes could be minutes old — their age may round onto the 15-minute grid.
+        [InlineData(true, true, 31, false)]
+        // The clock stepped back since the confirmation: the age is unknown.
+        [InlineData(true, true, -1, false)]
+        // The divergence lies in bytes the ledger never held (dropped by a cap): nothing dates them.
+        [InlineData(true, false, 1, false)]
+        // The pass itself is not fresh — the first pass after a restart never anchors.
+        [InlineData(false, true, 1, false)]
+        // Nothing was replaced.
+        [InlineData(true, true, null, false)]
+        public void Rewound_entry_is_fresh_only_when_the_bytes_it_replaced_were_confirmed_within_the_fresh_window(
+            bool passLinesAreFresh, bool entryAtRewindPointReplaced, int? secondsSinceConfirmed, bool expected)
+        {
+            var now = new DateTime(2026, 10, 4, 19, 2, 0, DateTimeKind.Utc);
+            DateTime? confirmed = secondsSinceConfirmed.HasValue ? now.AddSeconds(-secondsSinceConfirmed.Value) : (DateTime?)null;
+            Assert.Equal(expected, ImeLogTracker.RewoundEntryIsFresh(passLinesAreFresh, entryAtRewindPointReplaced, confirmed, now));
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerOverwriteRewindTests.WriterBoundary.cs

@@ -0,0 +1,368 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
+{
+    /// <summary>
+    /// Session 756970cf: IME launched a Win32 detection executor and a platform-script executor 15 ms apart, and both
+    /// opened AgentExecutor.log at the same end-of-file offset. The platform executor's shorter start block overwrote
+    /// the detection executor's, whose identity line the tracker never saw; the detection's end block (exit 1 and its
+    /// stdout), written at its own position behind its own start block, then sat behind the PLATFORM start block, and
+    /// "the nearest preceding marker owns the line" handed another script's output and exit code to the platform
+    /// script. These tests pin the writer boundary: an entry that is not exactly one CMTrace record is where one
+    /// writer's bytes end and another's begin, and nothing behind it belongs to the invocation in front of it.
+    /// </summary>
+    public sealed partial class ImeLogTrackerOverwriteRewindTests
+    {
+        private const string RaceUserId = "00000000-0000-0000-0000-000000000000";
+        private const string RacePlatformId = "1d6f0a52-3c4e-4b7a-9e21-5f8c7d2b9a10";
+        private const string RaceDetectionAppId = "8b2e4c71-6a9d-4f03-b5e8-2c7a1d9f4e36";
+        private const string RaceFillerAppId = "5e1c2b7d-0a4f-4c8e-9d36-7b2f1e8a4c50";
+        private const string ImeDir = @"C:\Program Files (x86)\Microsoft Intune Management Extension";
+        private const string DetectionStdout = "VERBOSE: === Sample Suite Detection Started ===\r\nWARNING: === DETECTION FAILED: Sample Suite is not installed ===";
+        private const string PlatformStdout = "=== bootstrap loader started ===\r\nInstaller finished (exit code 0).";
+
+        private static string EntryAt(string time, string message)
+            => $"<![LOG[{message}]LOG]!><time=\"{time}\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">\r\n";
+
+        /// <summary>The four lines every AgentExecutor invocation starts with — identical length for every executor.</summary>
+        private static string ExecutorBanner(string time)
+            => EntryAt(time, "ExecutorLog AgentExecutor gets invoked")
+            + EntryAt(time, "Creating command line parser, name delimiter is - and value separator is  .")
+            + EntryAt(time, "Getting Ordered Parameters")
+            + EntryAt(time, "Parsing Ordered Parameters.");
+
+        private static string ExecutorLaunch(string time, string scriptPath, string pid)
+            => EntryAt(time, "Prepare to run Powershell Script ..")
+            + EntryAt(time, $"cmd line for running powershell is -NoProfile -executionPolicy bypass -file  \"{scriptPath}\" ")
+            + EntryAt(time, "runAs32BitOn64 = False, so Disable Wow64FsRedirection")
+            + EntryAt(time, @"PowerShell path is C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe")
+            + EntryAt(time, $"[Executor] created powershell with process id {pid}");
+
+        private static string PlatformStartBlock(string time, string policyId, string pid)
+        {
+            var path = $@"{ImeDir}\Policies\Scripts\{RaceUserId}_{policyId}.ps1";
+            var results = $@"{ImeDir}\Policies\Results\{RaceUserId}_{policyId}";
+            return ExecutorBanner(time)
+                + EntryAt(time, $"Adding argument powershell with value {path} to the named argument list.")
+                + EntryAt(time, "Powershell option gets invoked")
+                + EntryAt(time, path)
+                + EntryAt(time, results + ".output")
+                + EntryAt(time, results + ".error")
+                + EntryAt(time, results + ".timeout")
+                + ExecutorLaunch(time, path, pid);
+        }
+
+        private static string DetectionStartBlock(string time, string appId, string pid)
+        {
+            var path = $@"{ImeDir}\Content\DetectionScripts\{appId}_2.ps1";
+            return ExecutorBanner(time)
+                + EntryAt(time, $"Adding argument powershellDetection with value {path} to the named argument list.")
+                + EntryAt(time, "PowershellDetection option gets invoked")
+                + EntryAt(time, path)
+                + EntryAt(time, path + "quotedResultFilePath.txt")
+                + EntryAt(time, path + "quotedErrorFilePath.txt")
+                + EntryAt(time, path + "quotedTimeoutFilePath.txt")
+                + EntryAt(time, path + "quotedExitCodeFilePath.txt")
+                + ExecutorLaunch(time, path, pid);
+        }
+
+        private static string ExecutorEndBlock(string time, int exitCode, string stdout)
+            => EntryAt(time, $"Powershell exit code is {exitCode}")
+            + EntryAt(time, $"length of out={stdout.Length}")
+            + EntryAt(time, "length of error=0")
+            + EntryAt(time, "error from script =")
+            + EntryAt(time, exitCode == 0 ? "Powershell script is successfully executed." : "Powershell script is failed to execute")
+            + EntryAt(time, $"write output done. output = {stdout}, error = ")
+            + EntryAt(time, "Revert Wow64FsRedirection")
+            + EntryAt(time, "Agent executor completed.");
+
+        private static string PlatformResultLine(string policyId)
+            => $"[PowerShell] User Id = {RaceUserId}, Policy id = {policyId}, policy result = Success";
+
+        /// <summary>The file offsets at which the entries of an ASCII <paramref name="block"/> start when it is written at <paramref name="at"/>.</summary>
+        private static HashSet<long> EntryStarts(string block, long at)
+        {
+            Assert.True(block.All(c => c < 128), "offset arithmetic assumes ASCII test content");
+            var starts = new HashSet<long>();
+            for (var i = block.IndexOf("<![LOG[", StringComparison.Ordinal); i >= 0; i = block.IndexOf("<![LOG[", i + 1, StringComparison.Ordinal))
+                starts.Add(at + i);
+            return starts;
+        }
+
+        [Fact]
+        public async Task Executor_that_opened_at_the_same_offset_never_lends_its_end_block_to_the_platform_script()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+
+            // An earlier, finished detection run: the race starts mid-file like in the field log.
+            h.Append(DetectionStartBlock("12:00:00.0000000", RaceFillerAppId, "1548") + ExecutorEndBlock("12:00:00.5000000", 0, "detected"));
+            await h.Pass();
+            var x = h.Length;
+
+            // Detection executor C and platform executor D open the file at the same end x. C writes first; the tracker
+            // reads C's banner, then D writes its own start block over C's.
+            var cStart = DetectionStartBlock("12:00:01.0000000", RaceDetectionAppId, "6416");
+            var dStart = PlatformStartBlock("12:00:01.2000000", RacePlatformId, "2524");
+            var cHead = cStart.Substring(0, cStart.IndexOf("<![LOG[Getting Ordered Parameters", StringComparison.Ordinal));
+            h.Append(cHead);
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+            h.Append(cStart.Substring(cHead.Length));
+            h.Overwrite(x, dStart);
+
+            // The field geometry: D's start block is shorter and ends inside one of C's lines, so the tail of that line
+            // sits between D's start block and C's remaining bytes.
+            Assert.True(dStart.Length < cStart.Length);
+            Assert.DoesNotContain(x + dStart.Length, EntryStarts(cStart, x));
+            h.Now = h.Now.AddMilliseconds(150);
+            await h.Pass();
+            Assert.True(h.Health.OverwriteRewinds >= 1);
+
+            // C ends: its end block lands at its own position, right behind its own (overwritten) start block.
+            Assert.Equal(x + cStart.Length, h.Length);
+            var cEnd = ExecutorEndBlock("12:00:07.0000000", 1, DetectionStdout);
+            h.Append(cEnd);
+            h.Now = h.Now.AddSeconds(6);
+            await h.Pass();
+
+            // IME's result for D reaches the tracker before D's own end block: the completion must wait for it.
+            h.Tracker.ProcessLogMessageForTest(PlatformResultLine(RacePlatformId), sourceFileName: "IntuneManagementExtension.log");
+            Assert.Empty(h.Completed);
+
+            // D ends: its end block lands at ITS position, over the fragment and C's bytes; C's last line survives.
+            var dEnd = ExecutorEndBlock("12:00:09.5000000", 0, PlatformStdout);
+            Assert.True(dEnd.Length < cStart.Length - dStart.Length + cEnd.Length);
+            h.Overwrite(x + dStart.Length, dEnd);
+            h.Now = h.Now.AddMilliseconds(130);
+            await h.Pass();
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now);
+
+            var script = Assert.Single(h.Completed);
+            Assert.Equal(RacePlatformId, script.PolicyId);
+            Assert.Equal("Success", script.Result);
+            Assert.Equal(0, script.ExitCode);
+            Assert.Equal(PlatformStdout.Replace("\r\n", "\n"), script.Stdout);
+            Assert.DoesNotContain(h.Completed, s => (s.Stdout ?? string.Empty).Contains("Detection"));
+
+            // The run is known to the registry reconciliation under the user id of its own lines (D-316).
+            Assert.Equal(RaceUserId, script.UserId);
+            Assert.False(string.IsNullOrEmpty(script.RunId));
+            h.Tracker.ScriptRuns.NotePassCompleted(DateTime.MaxValue.AddDays(-1));
+            Assert.Equal(PlatformRunClaim.Claimed, h.Tracker.ScriptRuns.TryClaim(RaceUserId, RacePlatformId, h.Now, out var run));
+            Assert.Equal(script.RunId, run!.RunId);
+        }
+
+        /// <summary>
+        /// The mirror image: a foreign executor whose stream position lies inside the platform start block (it opened
+        /// at the same end with a shorter start block) writes its end block there. Its first line merges with the head of
+        /// a platform line — cut inside the message or inside the trailer, which the parser would otherwise read up to
+        /// the foreign trailer — and its output line follows without any marker in between.
+        /// </summary>
+        [Theory]
+        [InlineData(15)]
+        [InlineData(-30)]
+        public async Task Foreign_end_block_merged_into_the_platform_start_block_never_reaches_the_platform_script(int cut)
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(DetectionStartBlock("12:00:00.0000000", RaceFillerAppId, "1548") + ExecutorEndBlock("12:00:00.5000000", 0, "detected"));
+            await h.Pass();
+            var x = h.Length;
+
+            var dStart = PlatformStartBlock("12:00:01.0000000", RacePlatformId, "2524");
+            h.Append(dStart);
+            await h.Pass();
+
+            // The foreign end block starts inside the line after D's argument line.
+            var lineAfterArgument = x + dStart.IndexOf("<![LOG[Powershell option gets invoked", StringComparison.Ordinal);
+            var lineLength = EntryAt("12:00:01.0000000", "Powershell option gets invoked").Length;
+            var at = lineAfterArgument + (cut > 0 ? cut : lineLength + cut);
+            var foreignEnd = ExecutorEndBlock("12:00:03.0000000", 1, "foreign output");
+            Assert.True(at + foreignEnd.Length < x + dStart.Length, "the foreign block must end inside D's start block");
+            h.Overwrite(at, foreignEnd);
+            h.Tracker.RequestOverwriteCheckForTest();
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+
+            h.Tracker.ProcessLogMessageForTest(PlatformResultLine(RacePlatformId), sourceFileName: "IntuneManagementExtension.log");
+            h.Now = h.Now.Add(ImeLogTracker.PlatformScriptEndBlockGrace);
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now);
+
+            // No owner is provable behind the cut: the completion goes out without end-block data, never with the foreign one.
+            var script = Assert.Single(h.Completed);
+            Assert.Equal("Success", script.Result);
+            Assert.Null(script.ExitCode);
+            Assert.Null(script.Stdout);
+        }
+
+        [Fact]
+        public async Task Entry_read_unchanged_after_a_rewind_keeps_its_platform_marker()
+        {
+            const string platformId = "2b7d9e41-8c3a-4f60-a5d2-9e1b7c4f3a08";
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+
+            // Detection W waits for its script; detection X runs completely behind it; platform F starts behind X.
+            var wStart = DetectionStartBlock("12:00:00.0000000", RaceFillerAppId, "1111");
+            var xRun = DetectionStartBlock("12:00:00.2000000", RaceDetectionAppId, "2222") + ExecutorEndBlock("12:00:00.4000000", 0, "x detected");
+            h.Append(wStart + xRun + PlatformStartBlock("12:00:01.0000000", platformId, "3333"));
+            await h.Pass();
+
+            // W ends at its own position, over the head of X's run; F's start block keeps its bytes and offset.
+            var wEnd = ExecutorEndBlock("12:00:02.0000000", 0, "w detected");
+            Assert.True(wEnd.Length < xRun.Length);
+            h.Overwrite(wStart.Length, wEnd);
+            h.Tracker.RequestOverwriteCheckForTest();
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+            Assert.Equal(1, h.Health.OverwriteRewinds);
+
+            // F's end block lands behind its start block: still F's, because F's marker survived with its bytes.
+            h.Append(ExecutorEndBlock("12:00:05.0000000", 7, "Hello from F"));
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+            h.Tracker.ProcessLogMessageForTest(PlatformResultLine(platformId), sourceFileName: "IntuneManagementExtension.log");
+
+            var script = Assert.Single(h.Completed);
+            Assert.Equal(platformId, script.PolicyId);
+            Assert.Equal(7, script.ExitCode);
+            Assert.Equal("Hello from F", script.Stdout);
+        }
+
+        [Fact]
+        public async Task Writer_boundary_read_unchanged_after_a_rewind_still_closes_the_platform_invocation()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+
+            // Detection Q waits for its script while detection R runs completely behind it.
+            var qStart = DetectionStartBlock("12:00:00.0000000", RaceFillerAppId, "1111");
+            var rRun = DetectionStartBlock("12:00:00.2000000", "6c3f8a20-1d5e-4b97-8f4a-0e2d6b9c7a13", "2222") + ExecutorEndBlock("12:00:00.4000000", 0, "r detected");
+            h.Append(qStart + rRun);
+            await h.Pass();
+            var x = h.Length;
+
+            // The race of the field case behind them: the boundary closes D.
+            var cStart = DetectionStartBlock("12:00:01.0000000", RaceDetectionAppId, "6416");
+            var dStart = PlatformStartBlock("12:00:01.2000000", RacePlatformId, "2524");
+            h.Append(cStart);
+            h.Overwrite(x, dStart);
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+
+            // Q ends at its own position, over R's run: the rewind starts in front of the race, whose bytes read unchanged.
+            var qEnd = ExecutorEndBlock("12:00:02.0000000", 0, "q detected");
+            Assert.True(qEnd.Length < rRun.Length);
+            h.Overwrite(qStart.Length, qEnd);
+            h.Tracker.RequestOverwriteCheckForTest();
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+
+            // C's end block behind the boundary stays unowned; D's own end block completes D.
+            var cEnd = ExecutorEndBlock("12:00:07.0000000", 1, DetectionStdout);
+            h.Append(cEnd);
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+            h.Tracker.ProcessLogMessageForTest(PlatformResultLine(RacePlatformId), sourceFileName: "IntuneManagementExtension.log");
+            Assert.Empty(h.Completed);
+
+            h.Overwrite(x + dStart.Length, ExecutorEndBlock("12:00:09.5000000", 0, PlatformStdout));
+            h.Now = h.Now.AddMilliseconds(130);
+            await h.Pass();
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now);
+
+            var script = Assert.Single(h.Completed);
+            Assert.Equal(0, script.ExitCode);
+            Assert.Equal(PlatformStdout.Replace("\r\n", "\n"), script.Stdout);
+        }
+
+        [Fact]
+        public async Task Raw_text_in_the_executor_log_is_never_matched_and_closes_the_platform_invocation()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(PlatformStartBlock("12:00:00.0000000", RacePlatformId, "2524"));
+            await h.Pass();
+
+            // The tail of a cut line that happens to read like an exit line, then a foreign end block.
+            h.Append("Powershell exit code is 5\r\n" + ExecutorEndBlock("12:00:02.0000000", 6, "foreign output"));
+            // A fragment right at the bookmark stops the first pass for a check; the second one reads it.
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+
+            h.Tracker.ProcessLogMessageForTest(PlatformResultLine(RacePlatformId), sourceFileName: "IntuneManagementExtension.log");
+            h.Now = h.Now.Add(ImeLogTracker.PlatformScriptEndBlockGrace);
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now);
+
+            var script = Assert.Single(h.Completed);
+            Assert.Null(script.ExitCode);
+            Assert.Null(script.Stdout);
+        }
+
+        [Fact]
+        public async Task Fragment_in_the_ime_log_does_not_close_the_platform_run_context()
+        {
+            using var h = new Harness("IntuneManagementExtension.log", ScriptPatterns());
+            // In the IME log the service writes the platform marker and the context line itself; the fragment in
+            // between is the tail of an executor's telemetry line and separates nothing.
+            h.Append(Entry(@"Script file C:\Program Files (x86)\Microsoft Intune Management Extension\Policies\Scripts\" + RaceUserId + "_" + RacePlatformId + ".ps1 is generated.", "17")
+                + "ing mananger...]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">\r\n"
+                + Entry("Launch powershell executor in user session", "17"));
+            await h.Pass();
+
+            h.Tracker.ProcessLogMessageForTest(PlatformResultLine(RacePlatformId));
+            h.Now = h.Now.Add(ImeLogTracker.PlatformScriptEndBlockGrace);
+            h.Tracker.FlushPendingPlatformScriptResults(h.Now);
+
+            var script = Assert.Single(h.Completed);
+            Assert.Equal("User", script.RunContext);
+        }
+
+        [Fact]
+        public async Task Cut_multi_line_output_adds_one_boundary_not_one_per_line()
+        {
+            using var h = new Harness("AgentExecutor.log", ScriptPatterns());
+            h.Append(PlatformStartBlock("12:00:00.0000000", RacePlatformId, "2524"));
+            await h.Pass();
+            var markersBefore = h.Tracker.InvocationMarkerCountForTest("AgentExecutor.log");
+
+            var lines = string.Concat(Enumerable.Range(1, 600).Select(i => $"orphaned output line {i}\r\n"));
+            h.Append(lines);
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+            h.Now = h.Now.AddMilliseconds(100);
+            await h.Pass();
+
+            Assert.Equal(markersBefore + 1, h.Tracker.InvocationMarkerCountForTest("AgentExecutor.log"));
+        }
+
+        [Theory]
+        [InlineData("<![LOG[Powershell exit code is 0]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", true)]
+        [InlineData("<![LOG[write output done. output = line one\nline two, error = ]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", true)]
+        [InlineData("\uFEFF<![LOG[ExecutorLog AgentExecutor gets invoked]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", true)]
+        [InlineData("t code is 3]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", false)]
+        [InlineData("", false)]
+        [InlineData("<![LOG[Powe<![LOG[Powershell exit code is 1]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", false)]
+        [InlineData("<![LOG[Powershell option gets invoked]LOG]!><time=\"12:00:00.0000000\" da<![LOG[Powershell exit code is 1]LOG]!><time=\"12:00:01.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", false)]
+        [InlineData("<![LOG[write output done. output = line one\nline<![LOG[Agent executor completed.]LOG]!><time=\"12:00:00.0000000\" date=\"9-10-2026\" component=\"AgentExecutor\" context=\"\" type=\"1\" thread=\"1\" file=\"\">", false)]
+        public void Single_cmtrace_record_is_told_apart_from_the_cut_of_two_writers(string text, bool expected)
+        {
+            Assert.Equal(expected, ImeLogTracker.IsSingleCmTraceRecord(text));
+        }
+
+        [Theory]
+        [InlineData("AgentExecutor.log", true)]
+        [InlineData("AgentExecutor-20261003-233348.log", true)]
+        [InlineData("IntuneManagementExtension.log", false)]
+        [InlineData("IntuneManagementExtension-20261003-233348.log", false)]
+        [InlineData("HealthScripts.log", false)]
+        [InlineData("AppWorkload.log", false)]
+        public void Writer_boundaries_apply_to_the_executor_log_live_and_rotated(string fileName, bool expected)
+        {
+            Assert.Equal(expected, ImeLogTracker.IsWriterBoundaryLogFile(fileName));
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerOverwriteRewindTests.cs

@@ -25,7 +25,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
     /// contract: unchanged bytes never rewind, changed bytes are processed exactly once, and the
     /// executor lines a rewind uncovers belong to the invocation that owns their file position.
     /// </summary>
-    public sealed class ImeLogTrackerOverwriteRewindTests
+    public sealed partial class ImeLogTrackerOverwriteRewindTests
     {
         private static readonly DateTime T0 = new DateTime(2026, 9, 10, 19, 30, 0, DateTimeKind.Utc);
 
@@ -42,7 +42,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
         private static readonly string[] ScriptPatternIds =
         {
             "PS-AGENT-INVOCATION", "PS-AGENT-ARG", "PS-AGENT-SCRIPT-START", "PS-AGENT-EXITCODE",
-            "PS-AGENT-OUTPUT", "PS-AGENT-COMPLETED", "PS-SCRIPT-GENERATED", "PS-SCRIPT-CONTEXT", "PS-SCRIPT-RESULT",
+            "PS-AGENT-OUTPUT", "PS-AGENT-ERROR", "PS-AGENT-COMPLETED", "PS-SCRIPT-GENERATED", "PS-SCRIPT-CONTEXT", "PS-SCRIPT-RESULT",
         };
 
         /// <summary>The shipped pattern JSON — the same source combine.js embeds — so the contract is the real one.</summary>
@@ -502,6 +502,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
         public async Task Ime_result_line_hidden_by_an_executor_start_line_is_recovered_from_the_ime_log()
         {
             using var h = new Harness("IntuneManagementExtension.log", ScriptPatterns());
+            // Seen empty first: the start lines are fresh and anchor themselves like the recovered result line will,
+            // so start and result sit on one timeline whatever the host's own zone is.
+            h.Append(string.Empty);
+            await h.Pass();
             h.Append(Entry(GeneratedLine, "17") + Entry("Launch powershell executor in user session", "17") + Entry("process id = 10608", "17"));
             await h.Pass();
             var servicePosition = h.Length;

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerPlatformScriptFallbackTests.cs

@@ -83,8 +83,33 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
             Assert.Single(emitted);
         }
 
+        [Theory]
+        // IME's verdict is Success exactly when the error file is empty, whatever the exit code. Judged by the exit
+        // code, session 67ae751c showed exit 0 with the script's own stderr as Success, and 46a41a0a an exit 1 without
+        // stderr as Failed, a run IME reported as Success one cycle earlier.
+        [InlineData(0, "Invoke-WebRequest : The remote name could not be resolved", "Failed")]
+        [InlineData(1, "", "Success")]
+        [InlineData(1, "  \n", "Success")]
+        [InlineData(0, "", "Success")]
+        [InlineData(1, null, "Failed")]
+        [InlineData(0, null, "Success")]
+        public void Fallback_judges_like_ime_by_the_stderr_it_read(int exitCode, string? stderr, string expected)
+        {
+            using var tmp = new TempDirectory();
+            var tracker = BuildTracker(tmp, out var emitted);
+            var observedAt = new DateTime(2026, 6, 19, 12, 59, 4, DateTimeKind.Utc);
+
+            tracker.SeedPendingPlatformScriptForTesting("0d2294bf", exitCode: exitCode, exitObservedAtUtc: observedAt, stderr: stderr);
+            tracker.FlushPendingPlatformScriptResults(observedAt.AddSeconds(20));
+
+            var script = Assert.Single(emitted);
+            Assert.Equal(expected, script.Result);
+            Assert.Equal(exitCode, script.ExitCode);
+            Assert.Equal("agentexecutor_fallback", script.ResultSource);
+        }
+
         [Fact]
-        public void Nonzero_exit_code_emits_failed_result()
+        public void Nonzero_exit_code_without_a_stderr_line_emits_failed_result()
         {
             using var tmp = new TempDirectory();
             var tracker = BuildTracker(tmp, out var emitted);

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/Ime/ImeLogTrackerScriptStatePersistenceTests.cs

@@ -108,6 +108,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
 
             var tracker = BuildTracker(tmp, out var emitted);
             tracker.LoadStateForTest(); // must not throw
+            Assert.Equal(0, tracker.ParkedPlatformScriptCountForTest);
 
             // Degrades to pre-fix behavior: no markers restored, normal emission works (the
             // result waits for its end block until the shutdown flush).
@@ -116,6 +117,32 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.Ime
             Assert.Single(emitted);
         }
 
+        [Fact]
+        public void Pending_slot_from_a_state_file_without_executor_start_loads_and_completes()
+        {
+            using var tmp = new TempDirectory();
+            var started = new DateTime(2026, 10, 4, 9, 0, 0, DateTimeKind.Utc);
+
+            // A pending slot written by an agent before runs carried their executor start and run id.
+            var persistence = new ImeTrackerStatePersistence(tmp.Path, new AgentLogger(tmp.Path, AgentLogLevel.Info));
+            persistence.Save(new ImeTrackerStateData
+            {
+                PendingPlatformScripts = new List<ScriptExecutionState>
+                {
+                    new ScriptExecutionState { PolicyId = "policyF", ScriptType = "platform", StartedAtUtc = started, ExitCode = 0, ExitObservedAtUtc = started.AddSeconds(5), Stdout = "done", Stderr = "" },
+                },
+            });
+
+            var tracker = BuildTracker(tmp, out var emitted);
+            tracker.LoadStateForTest();
+            tracker.CompletePlatformScriptFromImeResultForTesting("policyF", "Success", started.AddSeconds(6));
+
+            var script = Assert.Single(emitted);
+            Assert.Equal("Success", script.Result);
+            Assert.Equal(0, script.ExitCode);
+            Assert.False(string.IsNullOrEmpty(script.RunId));
+        }
+
         [Fact]
         public void Stale_result_older_than_current_run_start_is_dropped()
         {

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/ShellCoreTrackerUpdatePageBackfillTests.cs

@@ -0,0 +1,225 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using AutopilotMonitor.Agent.V2.Core.Logging;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals;
+using AutopilotMonitor.Agent.V2.Core.Orchestration;
+using AutopilotMonitor.Agent.V2.Core.Tests.Harness;
+using AutopilotMonitor.Agent.V2.Core.Tests.Orchestration;
+using AutopilotMonitor.DecisionCore.Engine;
+using AutopilotMonitor.DecisionCore.Signals;
+using AutopilotMonitor.Shared;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring
+{
+    /// <summary>
+    /// The first run's update page backfill (<see cref="ShellCoreTracker.BackfillUpdatePageTelemetry"/>)
+    /// and the page a stop belongs to across backfill and live records. The first run has no
+    /// replay — its backfill is telemetry and nothing else, so a Hello-wizard start, an ESP exit
+    /// or an ESP failure in the window must not leave the tracker on any rail.
+    /// </summary>
+    public sealed class ShellCoreTrackerUpdatePageBackfillTests : IDisposable
+    {
+        private static readonly DateTime At = new DateTime(2026, 10, 5, 13, 10, 0, DateTimeKind.Utc);
+
+        private const string NdupStarted = "CloudExperienceHost Web App Activity started. CXID: 'OobeNDUP'.";
+        private const string RebootNdupStarted = "CloudExperienceHost Web App Activity started. CXID: 'RebootNDUP'.";
+        private const string AadHelloStarted = "CloudExperienceHost Web App Activity started. CXID: 'AADHello'.";
+        private const string PageStopped = "CloudExperienceHost Web App Activity stopped. Result: 'success'.";
+        private const string DownloadSucceeded =
+            "CloudExperienceHost Web App Event 1. Name: 'SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded'.";
+        private const string EspExit = "CommercialOOBE_ESPProgress_Page_Exiting";
+        private const string EspFailure = "CommercialOOBE_ESPProgress_Failure";
+        private const string WhiteGloveSuccess = "CommercialOOBE_ESPProgress_WhiteGlove_Success";
+
+        private readonly TempDirectory _tmp = new TempDirectory();
+        private readonly FakeSignalIngressSink _sink = new FakeSignalIngressSink();
+        private int _registryReads;
+
+        public void Dispose() => _tmp.Dispose();
+
+        private ShellCoreTracker Build() =>
+            new ShellCoreTracker("S1", "T1",
+                new InformationalEventPost(_sink, new VirtualClock(At)),
+                new AgentLogger(_tmp.Path, AgentLogLevel.Info),
+                helloTracker: null,
+                oobeUpdateRegistryReader: () => { _registryReads++; return Array.Empty<OobeUpdateRegistrySnapshot.KeyState>(); },
+                stateDirectory: Path.Combine(_tmp.Path, "state"));
+
+        private static void Live(ShellCoreTracker tracker, int eventId, string description, DateTime at, long recordId) =>
+            tracker.ProcessEvent(eventId, description, at, "Microsoft-Windows-Shell-Core", isBackfill: false, recordId: recordId);
+
+        private static ShellCoreRecord Record(int eventId, string description, DateTime at, long recordId) =>
+            new ShellCoreRecord(eventId, description, at, recordId);
+
+        private IReadOnlyList<IReadOnlyDictionary<string, object>> Pages() =>
+            _sink.Posted
+                .Where(p => p.Kind == DecisionSignalKind.InformationalEvent
+                    && p.Payload != null
+                    && p.Payload.TryGetValue(SignalPayloadKeys.EventType, out var et)
+                    && et == Constants.EventTypes.OobeUpdatePage)
+                .Select(p => (IReadOnlyDictionary<string, object>)p.TypedPayload!)
+                .ToList();
+
+        // ------------------------------------------------------------ first run ----
+
+        [Fact]
+        public void FirstRunBackfill_ReportsTheUpdatePage_AndNothingElse()
+        {
+            using var tracker = Build();
+            var raised = new List<string>();
+            tracker.HelloWizardStarted += (_, _) => raised.Add("hello");
+            tracker.FinalizingSetupPhaseTriggered += (_, reason) => raised.Add($"finalizing:{reason}");
+            tracker.EspExited += (_, _) => raised.Add("exit");
+            tracker.EspFailureDetected += (_, _) => raised.Add("failure");
+            tracker.WhiteGloveCompleted += (_, _) => raised.Add("whiteglove");
+
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppEvent, EspExit, At.AddMinutes(-41), 95),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppEvent, EspFailure, At.AddSeconds(-2430), 96),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppEvent, WhiteGloveSuccess, At.AddSeconds(-2420), 97),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At.AddMinutes(-40), 100),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppEventName, DownloadSucceeded, At.AddMinutes(-30), 101),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, AadHelloStarted, At.AddMinutes(-2), 110),
+            });
+
+            Assert.Empty(raised);
+            Assert.False(tracker.IsEspExitedForTest);
+            Assert.False(tracker.IsWhiteGloveDetectedForTest);
+            var pages = Pages();
+            Assert.Equal(new object[] { "page_started", "event_name" }, pages.Select(d => d["cxhEvent"]).ToArray());
+            Assert.All(pages, d => Assert.Equal(true, d["backfill"]));
+            // No agent_trace, no ESP or Hello event — only the two page rows.
+            Assert.Equal(2, _sink.Posted.Count);
+            // The registry shows the state now, not at the records' time.
+            Assert.Equal(0, _registryReads);
+        }
+
+        [Fact]
+        public void FirstRunBackfill_KeepsTheEventTimes()
+        {
+            using var tracker = Build();
+
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At.AddMinutes(-40), 100),
+            });
+
+            var posted = Assert.Single(_sink.Posted);
+            Assert.Equal(At.AddMinutes(-40), posted.OccurredAtUtc);
+        }
+
+        [Fact]
+        public void LiveStop_FindsThePageThatStartedBeforeTheAgent()
+        {
+            using var tracker = Build();
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At.AddMinutes(-40), 100),
+            });
+
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStopped, PageStopped, At.AddMinutes(5), 120);
+
+            var stop = Pages().Last();
+            Assert.Equal("page_stopped", stop["cxhEvent"]);
+            Assert.Equal("OobeNDUP", stop["page"]);
+            Assert.Equal(false, stop["backfill"]);
+        }
+
+        [Fact]
+        public void SameRecord_FromTheLiveWatcherAndTheFirstRunBackfill_IsReportedOnce()
+        {
+            // The live watcher is armed before the backfill reads, so both can deliver a record.
+            using var tracker = Build();
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At, 700);
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At, 700),
+            });
+
+            Assert.Single(Pages(), d => (string)d["cxhEvent"] == "page_started");
+        }
+
+        // ---------------------------------------------------- the page of a stop ----
+
+        [Fact]
+        public void ReplayedOlderStart_DoesNotTakeOverTheNextLiveStop()
+        {
+            // A restart replay reads records older than the live watcher's; before, its page start
+            // overwrote the live page and the next live stop was attributed to the old page.
+            using var tracker = Build();
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStarted, RebootNdupStarted, At, 900);
+            tracker.ReplayBackfillRecords(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At.AddMinutes(-20), 850),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppEventName, DownloadSucceeded, At.AddMinutes(-19), 851),
+            });
+
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStopped, PageStopped, At.AddMinutes(1), 901);
+
+            var stop = Pages().Last();
+            Assert.Equal("page_stopped", stop["cxhEvent"]);
+            Assert.Equal("RebootNDUP", stop["page"]);
+        }
+
+        [Fact]
+        public void BackfilledStop_BelongsToTheStartOfItsOwnBatch()
+        {
+            using var tracker = Build();
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStarted, RebootNdupStarted, At, 900);
+
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At.AddMinutes(-20), 850),
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStopped, PageStopped, At.AddMinutes(-18), 852),
+            });
+
+            var stop = Pages().Last();
+            Assert.Equal("page_stopped", stop["cxhEvent"]);
+            Assert.Equal("OobeNDUP", stop["page"]);
+            Assert.Equal(true, stop["backfill"]);
+        }
+
+        [Fact]
+        public void BackfilledStopWithoutItsStart_IsNotGivenTheLivePage()
+        {
+            using var tracker = Build();
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At, 900);
+
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStopped, PageStopped, At.AddMinutes(-18), 852),
+            });
+
+            Assert.DoesNotContain(Pages(), d => (string)d["cxhEvent"] == "page_stopped");
+        }
+
+        [Fact]
+        public void NewerBackfilledStart_MovesTheLivePageForward()
+        {
+            // Records written between arming the watcher and the backfill's read are newer than
+            // the last live start the watcher delivered before them.
+            using var tracker = Build();
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStarted, NdupStarted, At, 900);
+            tracker.ReplayUpdatePageTelemetry(new[]
+            {
+                Record(ShellCoreTracker.EventId_ShellCore_WebAppStarted, RebootNdupStarted, At.AddSeconds(30), 905),
+            });
+
+            Live(tracker, ShellCoreTracker.EventId_ShellCore_WebAppStopped, PageStopped, At.AddMinutes(1), 906);
+
+            Assert.Equal("RebootNDUP", Pages().Last()["page"]);
+        }
+
+        [Fact]
+        public void UpdatePageLookback_IsInsideTheReplayClamp()
+        {
+            Assert.Equal(ShellCoreTracker.UpdatePageBackfillLookbackMinutes,
+                ShellCoreTracker.ClampLookbackMinutes(ShellCoreTracker.UpdatePageBackfillLookbackMinutes));
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/SystemSignals/ImeRegistryScriptResultObserverTests.cs

@@ -0,0 +1,411 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals;
+using AutopilotMonitor.Agent.V2.Core.Orchestration;
+using AutopilotMonitor.Agent.V2.Core.Tests.Harness;
+using AutopilotMonitor.Agent.V2.Core.Tests.Orchestration;
+using AutopilotMonitor.DecisionCore.Engine;
+using Xunit;
+using SharedEventTypes = AutopilotMonitor.Shared.Constants.EventTypes;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.SystemSignals
+{
+    /// <summary>
+    /// D-316: IME saves every platform script's result under Policies\&lt;user&gt;\&lt;policy&gt; after reporting the
+    /// batch; the observer checks the tracker's emitted run against it. The field case (session 756970cf): the run
+    /// had been given a Win32 detection script's end block — exit 1 and "Detection Started" output — while IME saved
+    /// the bootstrap output of the platform script itself.
+    /// </summary>
+    public sealed class ImeRegistryScriptResultObserverTests
+    {
+        private const string DeviceUser = "00000000-0000-0000-0000-000000000000";
+        private const string PolicyA = "1d6f0a52-3c4e-4b7a-9e21-5f8c7d2b9a10";
+        private const string PolicyB = "2b7d9e41-8c3a-4f60-a5d2-9e1b7c4f3a08";
+        private const string OwnStdout = "=== bootstrap loader started ===\nInstaller finished (exit code 0).";
+        private const string ForeignStdout = "VERBOSE: === Sample Suite Detection Started ===\nWARNING: === DETECTION FAILED ===";
+        private static readonly DateTime T0 = new DateTime(2026, 10, 3, 20, 59, 0, DateTimeKind.Utc);
+
+        // ── PlatformOutputJudge ─────────────────────────────────────────────────
+
+        private static PlatformScriptRun Run(string? stdout, string? stderr = null, int? exitCode = 0, string result = "Success", string resultSource = "ime_policy_result")
+            => new PlatformScriptRun { PolicyId = PolicyA, UserId = DeviceUser, RunId = "run-1", Emitted = true, Result = result, ResultSource = resultSource, ExitCode = exitCode, Stdout = stdout, Stderr = stderr };
+
+        private static string Details(string executionMessage)
+            => "{\"Version\":1,\"SigningCode\":15,\"EncryptionCode\":19,\"ExecutionMsg\":" + System.Text.Json.JsonSerializer.Serialize(executionMessage) + "}";
+
+        private static SavedScriptResult Saved(string? executionMessage, string result = "Success", int errorCode = 0, string user = DeviceUser, string policy = PolicyA, string stamp = "10/3/2026 9:00:00 PM")
+            => new SavedScriptResult
+            {
+                UserId = user,
+                PolicyId = policy,
+                Result = result,
+                ErrorCode = errorCode,
+                ResultDetails = executionMessage == null ? null : Details(executionMessage),
+                LastUpdatedTimeUtc = stamp,
+            };
+
+        [Fact]
+        public void Field_case_detection_output_on_the_platform_run_is_foreign_and_the_saved_stdout_replaces_it()
+        {
+            var judgement = PlatformOutputJudge.Judge(Run(ForeignStdout, string.Empty, exitCode: 1), Saved(OwnStdout.Replace("\n", "\r\n")));
+            Assert.Equal(PlatformOutputVerdict.Foreign, judgement.Verdict);
+            Assert.Equal("stdout_differs", judgement.Reason);
+            Assert.Equal(OwnStdout, judgement.Stdout);
+            Assert.Equal(string.Empty, judgement.Stderr);
+        }
+
+        [Fact]
+        public void Matching_output_is_verified_across_line_ending_and_trim_differences()
+        {
+            var judgement = PlatformOutputJudge.Judge(Run(OwnStdout, string.Empty), Saved("  " + OwnStdout.Replace("\n", "\r\n") + "\r\n"));
+            Assert.Equal(PlatformOutputVerdict.Verified, judgement.Verdict);
+        }
+
+        [Fact]
+        public void Output_cut_by_the_tracker_is_verified_against_the_longer_saved_text()
+        {
+            var full = string.Concat(Enumerable.Repeat("line of output\n", 1000)).TrimEnd();
+            var emitted = ImeLogTracker.TruncateOutput(full);
+            Assert.EndsWith(ImeLogTracker.OutputTruncationMarker, emitted);
+            Assert.Equal(PlatformOutputVerdict.Verified, PlatformOutputJudge.Judge(Run(emitted), Saved(full)).Verdict);
+        }
+
+        [Fact]
+        public void Both_empty_is_verified_but_stderr_on_a_success_is_another_executors()
+        {
+            Assert.Equal(PlatformOutputVerdict.Verified, PlatformOutputJudge.Judge(Run(string.Empty), Saved(string.Empty)).Verdict);
+            var judgement = PlatformOutputJudge.Judge(Run(string.Empty, "Get-Item : not found"), Saved(string.Empty));
+            Assert.Equal(PlatformOutputVerdict.Foreign, judgement.Verdict);
+            Assert.Equal("stderr_on_success", judgement.Reason);
+        }
+
+        [Fact]
+        public void Explicitly_empty_emitted_output_against_saved_text_is_foreign()
+        {
+            Assert.Equal(PlatformOutputVerdict.Foreign, PlatformOutputJudge.Judge(Run(string.Empty), Saved(OwnStdout)).Verdict);
+            Assert.Equal(PlatformOutputVerdict.Foreign, PlatformOutputJudge.Judge(Run(OwnStdout), Saved(string.Empty)).Verdict);
+        }
+
+        [Fact]
+        public void Output_never_read_is_completed_from_the_saved_text_and_the_exit_code_stands()
+        {
+            var judgement = PlatformOutputJudge.Judge(Run(null), Saved(OwnStdout));
+            Assert.Equal(PlatformOutputVerdict.Repaired, judgement.Verdict);
+            Assert.Equal("stdout_missing", judgement.Reason);
+            Assert.Equal(OwnStdout, judgement.Stdout);
+            Assert.Equal(PlatformOutputVerdict.NotComparable, PlatformOutputJudge.Judge(Run(null), Saved(string.Empty)).Verdict);
+        }
+
+        [Fact]
+        public void Stdout_containing_the_output_error_separator_is_repaired_not_foreign()
+        {
+            // "write output done. output = X, error = " with X = "Copying files, error = 0 errors\nDone": the
+            // lazy split leaves "Copying files" as stdout and the rest as stderr.
+            var judgement = PlatformOutputJudge.Judge(
+                Run("Copying files", "0 errors\nDone, error ="),
+                Saved("Copying files, error = 0 errors\r\nDone"));
+            Assert.Equal(PlatformOutputVerdict.Repaired, judgement.Verdict);
+            Assert.Equal("stdout_split", judgement.Reason);
+            Assert.Equal("Copying files, error = 0 errors\nDone", judgement.Stdout);
+            Assert.Equal(string.Empty, judgement.Stderr);
+        }
+
+        [Fact]
+        public void A_prefix_without_the_split_explanation_is_foreign()
+        {
+            Assert.Equal(PlatformOutputVerdict.Foreign, PlatformOutputJudge.Judge(Run("Detected"), Saved("Detected and repaired")).Verdict);
+        }
+
+        [Fact]
+        public void Failed_with_stderr_is_judged_on_stderr()
+        {
+            Assert.Equal(PlatformOutputVerdict.Verified,
+                PlatformOutputJudge.Judge(Run("partial", "Access denied", 1, "Failed"), Saved("Access denied\r\n", "Failed", 99)).Verdict);
+
+            var missing = PlatformOutputJudge.Judge(Run(null, null, 1, "Failed"), Saved("Access denied", "Failed", 99));
+            Assert.Equal(PlatformOutputVerdict.Repaired, missing.Verdict);
+            Assert.Null(missing.Stdout);
+            Assert.Equal("Access denied", missing.Stderr);
+
+            var foreign = PlatformOutputJudge.Judge(Run("Detected", string.Empty, 0, "Failed"), Saved("Access denied", "Failed", 99));
+            Assert.Equal(PlatformOutputVerdict.Foreign, foreign.Verdict);
+            Assert.Equal(string.Empty, foreign.Stdout);
+            Assert.Equal("Access denied", foreign.Stderr);
+        }
+
+        [Fact]
+        public void Results_without_saved_output_or_from_another_run_are_not_compared()
+        {
+            Assert.Equal("no_saved_output", PlatformOutputJudge.Judge(Run(OwnStdout, null, 1, "Failed"), Saved("1", "Failed", 1)).Reason);
+            var hashMismatch = new SavedScriptResult { UserId = DeviceUser, PolicyId = PolicyA, Result = "Failed", ErrorCode = 2, ResultDetails = "Hash mismatch" };
+            Assert.Equal("no_execution_message", PlatformOutputJudge.Judge(Run(OwnStdout, null, 1, "Failed"), hashMismatch).Reason);
+            Assert.Equal("result_differs", PlatformOutputJudge.Judge(Run(OwnStdout), Saved("Access denied", "Failed", 99)).Reason);
+            // A result derived from the exit code (fallback) is not IME's — the saved one is.
+            Assert.Equal(PlatformOutputVerdict.Verified,
+                PlatformOutputJudge.Judge(Run(OwnStdout, null, 1, "Failed", "agentexecutor_fallback"), Saved(OwnStdout)).Verdict);
+        }
+
+        // ── PlatformScriptRunRegister ───────────────────────────────────────────
+
+        private static ScriptExecutionState Emitted(string policyId, string? stdout, int? exitCode = 0, string? userId = DeviceUser, string runId = "run-1")
+            => new ScriptExecutionState { PolicyId = policyId, ScriptType = "platform", UserId = userId, RunId = runId, Result = "Success", ResultSource = "ime_policy_result", ExitCode = exitCode, Stdout = stdout };
+
+        [Fact]
+        public void A_save_is_paired_only_after_the_tracker_read_past_it_and_the_run_was_emitted()
+        {
+            var runs = new PlatformScriptRunRegister();
+            runs.NoteStarted(DeviceUser, PolicyA, T0);
+            var seen = T0.AddSeconds(30);
+
+            Assert.Equal(PlatformRunClaim.Wait, runs.TryClaim(DeviceUser, PolicyA, seen, out _));
+            runs.NotePassCompleted(seen.AddSeconds(1));
+            Assert.Equal(PlatformRunClaim.Wait, runs.TryClaim(DeviceUser, PolicyA, seen, out _)); // pass started too early
+            runs.NotePassCompleted(seen + PlatformScriptRunRegister.TrackerCatchUp);
+            Assert.Equal(PlatformRunClaim.Wait, runs.TryClaim(DeviceUser, PolicyA, seen, out _)); // run not emitted yet
+
+            runs.NoteEmitted(Emitted(PolicyA, OwnStdout), T0.AddSeconds(40));
+            Assert.Equal(PlatformRunClaim.Claimed, runs.TryClaim(DeviceUser, PolicyA, seen, out var run));
+            Assert.Equal("run-1", run!.RunId);
+            Assert.Equal(OwnStdout, run.Stdout);
+            Assert.Equal(PlatformRunClaim.None, runs.TryClaim(DeviceUser, PolicyA, seen, out _)); // never twice
+        }
+
+        [Fact]
+        public void A_new_start_replaces_the_latest_run_of_its_key_and_other_users_stay_apart()
+        {
+            var runs = new PlatformScriptRunRegister();
+            runs.NoteStarted(DeviceUser, PolicyA, T0);
+            runs.NoteEmitted(Emitted(PolicyA, "first run"), T0.AddSeconds(5));
+            runs.NoteStarted(DeviceUser, PolicyA, T0.AddMinutes(30));
+            runs.NoteEmitted(Emitted(PolicyA, "second run", runId: "run-2"), T0.AddMinutes(30).AddSeconds(5));
+            const string user = "6c3f8a20-1d5e-4b97-8f4a-0e2d6b9c7a13";
+            runs.NoteStarted(user, PolicyA, T0.AddMinutes(31));
+            runs.NotePassCompleted(T0.AddHours(1));
+
+            Assert.Equal(PlatformRunClaim.Claimed, runs.TryClaim(DeviceUser, PolicyA, T0.AddMinutes(31), out var run));
+            Assert.Equal("second run", run!.Stdout);
+            Assert.Equal(PlatformRunClaim.Wait, runs.TryClaim(user, PolicyA, T0.AddMinutes(32), out _));
+            Assert.Equal(PlatformRunClaim.None, runs.TryClaim(DeviceUser, PolicyB, T0.AddMinutes(32), out _));
+        }
+
+        [Fact]
+        public void A_run_without_a_readable_user_id_is_claimed_by_its_policy()
+        {
+            var runs = new PlatformScriptRunRegister();
+            runs.NoteStarted(null, PolicyA, T0);
+            runs.NoteEmitted(Emitted(PolicyA, OwnStdout, userId: null), T0.AddSeconds(5));
+            runs.NotePassCompleted(T0.AddMinutes(5));
+            Assert.Equal(PlatformRunClaim.Claimed, runs.TryClaim(DeviceUser, PolicyA, T0.AddMinutes(1), out _));
+        }
+
+        [Fact]
+        public void Register_keeps_the_newest_runs_and_its_counters_report_each_change_once()
+        {
+            var runs = new PlatformScriptRunRegister();
+            for (var i = 0; i <= PlatformScriptRunRegister.MaxRuns; i++)
+                runs.NoteStarted(DeviceUser, Guid.NewGuid().ToString("D"), T0.AddSeconds(i));
+            runs.NoteStarted(DeviceUser, PolicyA, T0.AddHours(1));
+            runs.NoteEmitted(Emitted(PolicyA, OwnStdout), T0.AddHours(1));
+            runs.NotePassCompleted(T0.AddHours(2));
+            Assert.Equal(PlatformRunClaim.Claimed, runs.TryClaim(DeviceUser, PolicyA, T0.AddHours(1), out _));
+
+            Assert.False(runs.ConsumeCountersChanged());
+            runs.CountVerified();
+            runs.CountCorrected();
+            Assert.True(runs.ConsumeCountersChanged());
+            Assert.False(runs.ConsumeCountersChanged());
+            Assert.Equal(1, runs.Verified);
+            runs.RestoreCounters(7, 3);
+            Assert.Equal(7, runs.Verified);
+            Assert.Equal(3, runs.Corrected);
+        }
+
+        // ── observer flow ───────────────────────────────────────────────────────
+
+        private sealed class Fixture
+        {
+            public readonly FakeSignalIngressSink Sink = new FakeSignalIngressSink();
+            public readonly VirtualClock Clock = new VirtualClock(T0);
+            public readonly PlatformScriptRunRegister Runs = new PlatformScriptRunRegister();
+            public Dictionary<string, SavedScriptResult> Registry = new Dictionary<string, SavedScriptResult>(StringComparer.OrdinalIgnoreCase);
+            public readonly ImeRegistryScriptResultObserver Observer;
+
+            public Fixture()
+            {
+                Observer = new ImeRegistryScriptResultObserver(Runs, new InformationalEventPost(Sink, Clock), null, Clock,
+                    () => new Dictionary<string, SavedScriptResult>(Registry, StringComparer.OrdinalIgnoreCase));
+            }
+
+            public void Save(SavedScriptResult saved) => Registry[ImeRegistryScriptResultObserver.KeyOf(saved.UserId, saved.PolicyId)] = saved;
+
+            /// <summary>The tracker emitted a run, then kept polling past the save.</summary>
+            public void EmitRun(string policyId, string? stdout, int? exitCode, string runId)
+            {
+                Runs.NoteStarted(DeviceUser, policyId, Clock.UtcNow);
+                Runs.NoteEmitted(Emitted(policyId, stdout, exitCode, runId: runId), Clock.UtcNow);
+            }
+
+            public void TrackerCaughtUp() => Runs.NotePassCompleted(Clock.UtcNow);
+
+            public IReadOnlyList<FakeSignalIngressSink.PostedSignal> Corrections()
+                => Sink.Posted.Where(p => p.Payload != null
+                    && p.Payload.TryGetValue(SignalPayloadKeys.EventType, out var et)
+                    && et == SharedEventTypes.ScriptOutputReconciliation).ToList();
+        }
+
+        [Fact]
+        public void Field_case_end_to_end_the_save_corrects_the_run_with_a_warning_naming_it()
+        {
+            var f = new Fixture();
+            f.Save(Saved("an older run of another policy", policy: PolicyB, stamp: "10/2/2026 8:00:00 AM"));
+            f.Observer.Tick("baseline");
+
+            f.EmitRun(PolicyA, ForeignStdout, 1, "run-a");
+            f.Save(Saved(OwnStdout));
+            f.Clock.Advance(TimeSpan.FromSeconds(1));
+            f.Observer.Tick("registry_change");
+            Assert.Empty(f.Corrections()); // the tracker has not read past the save yet
+
+            f.Clock.Advance(PlatformScriptRunRegister.TrackerCatchUp);
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+
+            var correction = Assert.Single(f.Corrections());
+            var data = correction.Payload!;
+            Assert.Equal(PolicyA, data["policyId"]);
+            Assert.Equal("platform", data["scriptType"]);
+            Assert.Equal("run-a", data["runId"]);
+            Assert.Equal("foreign", data["outcome"]);
+            Assert.Equal("stdout_differs", data["reason"]);
+            Assert.Equal("Success", data["result"]);
+            Assert.Equal(OwnStdout, data["stdout"]);
+            Assert.Equal(string.Empty, data["stderr"]);
+            Assert.Equal("1", data["previousExitCode"]);
+            Assert.Equal("0", data["registryErrorCode"]);
+            Assert.Equal("Warning", data[SignalPayloadKeys.Severity]);
+            Assert.Equal("true", data[SignalPayloadKeys.ImmediateUpload]);
+            Assert.DoesNotContain("exitCode", data.Keys);
+            Assert.Equal(1, f.Runs.Corrected);
+            Assert.Equal(0, f.Runs.Verified);
+
+            // The same save read again changes nothing.
+            f.Clock.Advance(TimeSpan.FromMinutes(1));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+            Assert.Single(f.Corrections());
+        }
+
+        [Fact]
+        public void Confirmed_output_is_counted_and_emits_nothing()
+        {
+            var f = new Fixture();
+            f.Observer.Tick("baseline");
+            f.EmitRun(PolicyA, OwnStdout, 0, "run-a");
+            f.Save(Saved(OwnStdout));
+            f.Clock.Advance(TimeSpan.FromSeconds(1));
+            f.Observer.Tick("registry_change");
+            f.Clock.Advance(TimeSpan.FromSeconds(3));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+
+            Assert.Empty(f.Corrections());
+            Assert.Equal(1, f.Runs.Verified);
+        }
+
+        [Fact]
+        public void Completed_output_is_an_info_event_that_keeps_the_exit_code()
+        {
+            var f = new Fixture();
+            f.Observer.Tick("baseline");
+            f.EmitRun(PolicyA, null, 0, "run-a");
+            f.Save(Saved(OwnStdout));
+            f.Clock.Advance(TimeSpan.FromSeconds(1));
+            f.Observer.Tick("registry_change");
+            f.Clock.Advance(TimeSpan.FromSeconds(3));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+
+            var data = Assert.Single(f.Corrections()).Payload!;
+            Assert.Equal("repaired", data["outcome"]);
+            Assert.Equal("Info", data[SignalPayloadKeys.Severity]);
+            Assert.DoesNotContain("previousExitCode", data.Keys);
+        }
+
+        [Fact]
+        public void A_save_seen_before_its_run_was_emitted_waits_for_the_emit()
+        {
+            var f = new Fixture();
+            f.Observer.Tick("baseline");
+            f.Runs.NoteStarted(DeviceUser, PolicyA, f.Clock.UtcNow); // result held for its end block
+            f.Save(Saved(OwnStdout));
+            f.Observer.Tick("registry_change");
+            f.Clock.Advance(TimeSpan.FromSeconds(3));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+            Assert.Equal(0, f.Runs.Verified + f.Runs.Corrected);
+
+            f.Runs.NoteEmitted(Emitted(PolicyA, ForeignStdout, 1, runId: "run-a"), f.Clock.UtcNow);
+            f.Clock.Advance(TimeSpan.FromSeconds(60));
+            f.Observer.Tick("periodic");
+            Assert.Equal("foreign", Assert.Single(f.Corrections()).Payload!["outcome"]);
+        }
+
+        [Fact]
+        public void A_save_no_run_claims_within_the_expiry_is_dropped()
+        {
+            var f = new Fixture();
+            f.Observer.Tick("baseline");
+            f.Save(Saved(OwnStdout));
+            f.Observer.Tick("registry_change");
+            f.Clock.Advance(ImeRegistryScriptResultObserver.PendingExpiry);
+            f.TrackerCaughtUp();
+            f.Runs.NoteStarted(DeviceUser, PolicyA, f.Clock.UtcNow);
+            f.Observer.Tick("periodic"); // waits for the emit — and expires
+
+            f.Runs.NoteEmitted(Emitted(PolicyA, ForeignStdout, 1, runId: "run-a"), f.Clock.UtcNow);
+            f.Clock.Advance(TimeSpan.FromSeconds(60));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+            Assert.Empty(f.Corrections());
+        }
+
+        [Fact]
+        public void Saves_from_before_the_agent_started_are_the_silent_baseline()
+        {
+            var f = new Fixture();
+            f.EmitRun(PolicyA, ForeignStdout, 1, "run-a");
+            f.Save(Saved(OwnStdout));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("baseline");
+            f.Clock.Advance(TimeSpan.FromMinutes(1));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+
+            Assert.Empty(f.Corrections());
+            Assert.Equal(0, f.Runs.Verified + f.Runs.Corrected);
+        }
+
+        [Fact]
+        public void Corrections_beyond_the_cap_are_counted_but_not_emitted()
+        {
+            var f = new Fixture();
+            f.Observer.Tick("baseline");
+            var policies = Enumerable.Range(0, ImeRegistryScriptResultObserver.MaxCorrectionsPerSession + 3).Select(_ => Guid.NewGuid().ToString("D")).ToList();
+            foreach (var policy in policies)
+            {
+                f.EmitRun(policy, ForeignStdout, 1, "run-" + policy);
+                f.Save(Saved(OwnStdout, policy: policy));
+            }
+            f.Observer.Tick("registry_change");
+            f.Clock.Advance(TimeSpan.FromSeconds(3));
+            f.TrackerCaughtUp();
+            f.Observer.Tick("periodic");
+
+            Assert.Equal(ImeRegistryScriptResultObserver.MaxCorrectionsPerSession, f.Corrections().Count);
+            Assert.Equal(policies.Count, f.Runs.Corrected);
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/Monitoring/SystemSignals/OobeUpdateTelemetryTests.cs

@@ -101,15 +101,41 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.SystemSignals
         }
 
         [Fact]
-        public void PageEvents_AreCappedPerRun()
+        public void PageEvents_AreCappedPerRun_AndTheCapIsMarkedOnce()
         {
             var telemetry = Build();
             for (var i = 0; i < OobeUpdateTelemetry.MaxPageEventsPerRun + 20; i++)
             {
-                telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.EventName, 62406, name: $"ExpeditedUpdate_step{i}"), At, isBackfill: false);
+                telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.EventName, 62406, name: $"ExpeditedUpdate_step{i}"), At.AddSeconds(i), isBackfill: false);
             }
 
-            Assert.Equal(OobeUpdateTelemetry.MaxPageEventsPerRun, ByType(Constants.EventTypes.OobeUpdatePage).Count);
+            var pages = ByType(Constants.EventTypes.OobeUpdatePage);
+            Assert.Equal(OobeUpdateTelemetry.MaxPageEventsPerRun + 1, pages.Count);
+            // A name missing after the marker proves nothing — the rules check for it.
+            var marker = Data(pages.Last());
+            Assert.Equal(OobeUpdatePageRecord.NamesCapped, marker["cxhEvent"]);
+            Assert.Equal(false, marker["backfill"]);
+            Assert.Equal(OobeUpdateTelemetry.MaxPageEventsPerRun, marker["limit"]);
+            Assert.Equal(At.AddSeconds(OobeUpdateTelemetry.MaxPageEventsPerRun), pages.Last().OccurredAtUtc); // the first name over the budget
+        }
+
+        [Fact]
+        public void BackfilledNames_HaveTheirOwnBudget()
+        {
+            // The records from before the agent started cannot spend the live page's budget.
+            var telemetry = Build();
+            for (var i = 0; i < OobeUpdateTelemetry.MaxBackfillPageEventsPerRun + 5; i++)
+            {
+                telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.EventName, 62406, name: $"ExpeditedUpdate_old{i}"), At.AddMinutes(-30), isBackfill: true);
+            }
+
+            Assert.True(telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.EventName, 62406, name: "ExpeditedUpdate_live"), At, isBackfill: false));
+
+            var markers = ByType(Constants.EventTypes.OobeUpdatePage)
+                .Where(p => (string)Data(p)["cxhEvent"] == OobeUpdatePageRecord.NamesCapped).ToList();
+            var marker = Assert.Single(markers);
+            Assert.Equal(true, Data(marker)["backfill"]);
+            Assert.Equal(OobeUpdateTelemetry.MaxBackfillPageEventsPerRun, Data(marker)["limit"]);
         }
 
         [Fact]
@@ -123,12 +149,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Tests.Monitoring.SystemSignals
             }
 
             Assert.False(telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.EventName, 62406, name: "ExpeditedUpdate_late"), At, isBackfill: false));
+            Assert.False(telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.EventName, 62406, name: "ExpeditedUpdate_later"), At, isBackfill: false));
             Assert.True(telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.PageStarted, 62404, page: "RebootNDUP"), At.AddMinutes(1), isBackfill: false));
             Assert.True(telemetry.ReportPage(new OobeUpdatePageRecord(OobeUpdatePageRecord.PageStopped, 62405, page: "RebootNDUP", result: "success"), At.AddMinutes(2), isBackfill: false));
 
             var pages = ByType(Constants.EventTypes.OobeUpdatePage);
-            Assert.Equal(OobeUpdateTelemetry.MaxPageEventsPerRun + 2, pages.Count);
-            Assert.Equal(new object[] { "page_started", "page_stopped" },
+            Assert.Equal(OobeUpdateTelemetry.MaxPageEventsPerRun + 3, pages.Count);
+            Assert.Equal(new object[] { OobeUpdatePageRecord.NamesCapped, "page_started", "page_stopped" },
                 pages.Skip(OobeUpdateTelemetry.MaxPageEventsPerRun).Select(p => Data(p)["cxhEvent"]).ToArray());
         }
 

src/Agent/AutopilotMonitor.Agent.V2.Core.Tests/SignalAdapters/ImeLogTrackerAdapterPlatformRunTests.cs

@@ -0,0 +1,54 @@
+using System;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using AutopilotMonitor.Agent.V2.Core.SignalAdapters;
+using AutopilotMonitor.Agent.V2.Core.Tests.Harness;
+using SharedEventTypes = AutopilotMonitor.Shared.Constants.EventTypes;
+using Xunit;
+
+namespace AutopilotMonitor.Agent.V2.Core.Tests.SignalAdapters
+{
+    /// <summary>
+    /// D-316: every emitted platform-script completion carries a run id, and the tracker's run register holds what
+    /// was emitted for it under the IME user id — what the registry reconciliation pairs IME's saved result with.
+    /// </summary>
+    public sealed class ImeLogTrackerAdapterPlatformRunTests
+    {
+        private static readonly DateTime ClockNow = new DateTime(2026, 10, 3, 21, 0, 0, DateTimeKind.Utc);
+        private const string DeviceUser = "00000000-0000-0000-0000-000000000000";
+        private const string PolicyId = "1d6f0a52-3c4e-4b7a-9e21-5f8c7d2b9a10";
+
+        [Fact]
+        public void Platform_completion_carries_its_run_id_and_the_register_holds_the_emitted_run()
+        {
+            using var f = new ImeLogTrackerAdapterFixture(ClockNow);
+            using var adapter = new ImeLogTrackerAdapter(f.Tracker, f.Ingress, f.Clock);
+
+            f.Tracker.LastMatchedLogTimestamp = ClockNow.AddSeconds(-10);
+            f.Tracker.HandlePlatformScriptStarted(PolicyId, "ime", DeviceUser);
+            f.Tracker.RecordPlatformScriptExitCodeForTesting(PolicyId, 0, ClockNow.AddSeconds(-1));
+            f.Tracker.LastMatchedLogTimestamp = ClockNow;
+            f.Tracker.CompletePlatformScriptFromImeResultForTesting(PolicyId, "Success", ClockNow);
+
+            var info = f.InfoEvent(SharedEventTypes.ScriptCompleted);
+            Assert.True(Guid.TryParse(info.Payload!["runId"], out _));
+
+            f.Tracker.ScriptRuns.NotePassCompleted(ClockNow.AddMinutes(1));
+            Assert.Equal(PlatformRunClaim.Claimed, f.Tracker.ScriptRuns.TryClaim(DeviceUser, PolicyId, ClockNow.AddSeconds(5), out var run));
+            Assert.Equal(info.Payload["runId"], run!.RunId);
+            Assert.Equal(0, run.ExitCode);
+            Assert.Equal("Success", run.Result);
+        }
+
+        [Theory]
+        [InlineData("[PowerShell] User Id = 00000000-0000-0000-0000-000000000000, Policy id = d94468af-6ebe-4e94-9901-2a62d33ea6c1, policy result = Success", "00000000-0000-0000-0000-000000000000")]
+        [InlineData(@"Adding argument powershell with value C:\Program Files (x86)\Microsoft Intune Management Extension\Policies\Scripts\6C3F8A20-1D5E-4B97-8F4A-0E2D6B9C7A13_d94468af-6ebe-4e94-9901-2a62d33ea6c1.ps1", "6c3f8a20-1d5e-4b97-8f4a-0e2d6b9c7a13")]
+        [InlineData(@"Script file C:\Program Files (x86)\Microsoft Intune Management Extension\Policies\Scripts\00000000-0000-0000-0000-000000000000_d94468af-6ebe-4e94-9901-2a62d33ea6c1.ps1 is generated", "00000000-0000-0000-0000-000000000000")]
+        [InlineData(@"Adding argument powershellDetection with value C:\Program Files (x86)\Microsoft Intune Management Extension\Content\DetectionScripts\8b2e4c71-6a9d-4f03-b5e8-2c7a1d9f4e36_2.ps1", null)]
+        [InlineData("[PowerShell] User Id = not-a-guid, Policy id = d94468af", null)]
+        [InlineData("", null)]
+        public void Ime_user_id_is_read_from_the_result_line_and_the_script_path(string text, string? expected)
+        {
+            Assert.Equal(expected, ImeLogTracker.ImeUserIdFrom(text));
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ImeLogTracker.Handlers.cs

@@ -271,17 +271,42 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             }
             else
             {
-                HandlePlatformScriptStarted(id, source);
+                HandlePlatformScriptStarted(id, source, ImeUserIdFrom(match.Value));
             }
         }
 
+        /// <summary>
+        /// The IME user id on a platform-script line — <c>User Id = {id}</c> on the result line,
+        /// <c>…\Policies\Scripts\{id}_{policy}.ps1</c> on the start lines — or null. Read from the
+        /// matched text, not from a capture group, so it works with every pattern pack the agent may
+        /// be served.
+        /// </summary>
+        internal static string ImeUserIdFrom(string text)
+        {
+            if (string.IsNullOrEmpty(text)) return null;
+            const string resultTag = "User Id = ";
+            const string pathTag = @"\Policies\Scripts\";
+            var i = text.IndexOf(resultTag, StringComparison.OrdinalIgnoreCase);
+            if (i >= 0) return GuidAt(text, i + resultTag.Length);
+            i = text.IndexOf(pathTag, StringComparison.OrdinalIgnoreCase);
+            return i >= 0 ? GuidAt(text, i + pathTag.Length) : null;
+        }
+
+        private static string GuidAt(string text, int start)
+        {
+            if (start + 36 > text.Length) return null;
+            var candidate = text.Substring(start, 36);
+            return Guid.TryParse(candidate, out _) ? candidate.ToLowerInvariant() : null;
+        }
+
         // Platform script: AgentExecutor.log entries create/enrich, IME log entries also create.
         // Internal so the stale-slot hardening is directly testable (the public path arrives via
         // a regex Match).
-        internal void HandlePlatformScriptStarted(string id, string source = null)
+        internal void HandlePlatformScriptStarted(string id, string source = null, string userId = null)
         {
             var currentStartTs = LastMatchedLogTimestamp ?? UtcNowProvider();
             var currentStartProvenance = CaptureLastMatchedProvenance();
+            var fromExecutor = string.Equals(source, "agentexecutor", StringComparison.OrdinalIgnoreCase);
 
             // A start line older than the result this policy already emitted is the late start
             // line of THAT run: its AgentExecutor block surfaced after the IME result — the two
@@ -294,7 +319,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             // never tie; a low-resolution clock in a test may).
             if (_platformScriptResultEmitted.TryGetValue(id, out var emittedResultTs) && currentStartTs < emittedResultTs)
             {
-                RecordInvocationMarker(id, isClose: false);
+                RecordInvocationMarker(id, isClose: false, EmittedRunId);
                 NoteInvocationActivity();
                 _logger.Debug($"ImeLogTracker: platform script start line for {id} (source: {source ?? "ime"}) predates its emitted result — late line of that run, not a new one");
                 return;
@@ -302,7 +327,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
 
             if (_pendingPlatformScripts.TryGetValue(id, out var pendingSlot))
             {
-                if (pendingSlot.StartedAtUtc.HasValue && currentStartTs - pendingSlot.StartedAtUtc.Value > TimeSpan.FromHours(24))
+                if (pendingSlot.StartedAtUtc.HasValue && currentStartTs - pendingSlot.StartedAtUtc.Value > StalePlatformRunAge)
                 {
                     // Stale-slot hardening (session eaf3d8c4): a replayed start line from a previous
                     // enrollment whose matching result never appeared (script was mid-run when that
@@ -319,6 +344,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     // Emit what the held run has; its end block did not surface in time.
                     EmitPlatformScriptResult(pendingSlot, "the next run of this policy started");
                 }
+                else if (fromExecutor && LastMatchedLogTimestamp.HasValue && pendingSlot.Result == null
+                    && pendingSlot.ExecutorStartedAtUtc.HasValue && pendingSlot.ExecutorStartedAtUtc.Value < currentStartTs)
+                {
+                    // Every executor process writes its start line once: a later one is the next run
+                    // (IME re-runs a failed script on a later check-in), whose end block must not
+                    // overwrite this one's. This run waits for its IME result — on the first pass
+                    // AgentExecutor.log is read in full before the IME log (session eff1b413).
+                    ParkPlatformRun(pendingSlot);
+                }
                 else if (!pendingSlot.StartedAtUtc.HasValue)
                 {
                     // The slot was opened by its result while the start block was still hidden;
@@ -328,7 +362,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     _stateDirty = true;
                 }
             }
-            if (!_pendingPlatformScripts.ContainsKey(id))
+            if (_pendingPlatformScripts.TryGetValue(id, out var slot))
+            {
+                if (slot.UserId == null && userId != null) slot.UserId = userId;
+                if (fromExecutor && !slot.ExecutorStartedAtUtc.HasValue)
+                {
+                    slot.ExecutorStartedAtUtc = currentStartTs;
+                    _stateDirty = true;
+                }
+            }
+            else
             {
                 // A fresh start for this policy (no pending entry) begins a NEW execution.
                 // Clear any emitted-marker from a prior run so IME re-evaluations / retries of
@@ -336,24 +379,29 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 // deduped away. A start line of the emitted run itself never reaches this point
                 // (the guard above), so this never clears the current run's own marker.
                 _platformScriptResultEmitted.Remove(id);
-                _pendingPlatformScripts[id] = new ScriptExecutionState
+                slot = new ScriptExecutionState
                 {
                     PolicyId = id,
                     ScriptType = "platform",
+                    UserId = userId,
+                    RunId = NewRunId(),
                     // Prefer the source CMTrace timestamp so a script that started before the
                     // agent launched (replayed log content) is dated to its real start, not now.
                     // Set only at slot creation: the start line fires twice (agentexecutor + ime
                     // source) but the earliest wins.
                     StartedAtUtc = currentStartTs,
                     StartedAtProvenance = currentStartProvenance,
+                    ExecutorStartedAtUtc = fromExecutor ? currentStartTs : (DateTime?)null,
                 };
+                _pendingPlatformScripts[id] = slot;
+                ScriptRuns.NoteStarted(userId, id, UtcNowProvider());
                 // Live "running" indicator — same signal health scripts emit. Gated on slot
                 // creation so the duplicate start line (agentexecutor + ime source) doesn't
                 // double-emit for the same execution.
                 try { OnScriptStarted?.Invoke(new ScriptStartedInfo { PolicyId = id, ScriptType = "platform" }); }
                 catch (Exception ex) { _logger.Warning($"ImeLogTracker: OnScriptStarted handler threw: {ex.Message}"); }
             }
-            RecordInvocationMarker(id, isClose: false);
+            RecordInvocationMarker(id, isClose: false, LastMatchedLogTimestamp.HasValue ? RunIdOfStartLine(slot, fromExecutor, currentStartTs) : slot.RunId);
             NoteInvocationActivity();
             // Started lines fire twice per script (agentexecutor + ime source) and carry no
             // outcome — the matching `platform script completed` line below carries result+exit
@@ -361,6 +409,34 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             _logger.Debug($"ImeLogTracker: platform script started: {id} (source: {source ?? "ime"})");
         }
 
+        /// <summary>How long after IME's "Script file … is generated" line its executor writes its start line (about 2 s).</summary>
+        private static readonly TimeSpan ImeLaunchWindow = TimeSpan.FromMinutes(1);
+
+        /// <summary>
+        /// The run a timestamped start line belongs to, for its invocation marker. An executor start line belongs to the
+        /// slot unless it is older than the slot's executor start — re-read behind a later run — then to the parked run
+        /// it started. IME's "Script file … is generated" precedes its executor: it belongs to the live run whose
+        /// executor started within <see cref="ImeLaunchWindow"/> after it, else to a slot whose executor has not
+        /// started yet; otherwise its run is not known (yet) and the lines behind it go nowhere.
+        /// </summary>
+        private string RunIdOfStartLine(ScriptExecutionState slot, bool fromExecutor, DateTime lineTs)
+        {
+            if (fromExecutor)
+            {
+                if (!slot.ExecutorStartedAtUtc.HasValue || slot.ExecutorStartedAtUtc.Value <= lineTs) return slot.RunId;
+                var parked = _parkedPlatformScripts.FirstOrDefault(r =>
+                    string.Equals(r.PolicyId, slot.PolicyId, StringComparison.OrdinalIgnoreCase) && r.ExecutorStartedAtUtc == lineTs);
+                return parked?.RunId ?? EmittedRunId;
+            }
+
+            var launched = LivePlatformRuns(slot.PolicyId)
+                .Where(r => r.ExecutorStartedAtUtc.HasValue && r.ExecutorStartedAtUtc.Value >= lineTs && r.ExecutorStartedAtUtc.Value - lineTs <= ImeLaunchWindow)
+                .OrderBy(r => r.ExecutorStartedAtUtc.Value)
+                .FirstOrDefault();
+            if (launched != null) return launched.RunId;
+            return slot.ExecutorStartedAtUtc.HasValue ? EmittedRunId : slot.RunId;
+        }
+
         // Routes line-by-line script-data handlers (context / exitCode / output) to the right
         // accumulator based on the pattern's scriptType parameter. Health-script lines feed the
         // single-slot _pendingHealthScript (the HS-NEW-RESULT JSON delivers the full cycle in one
@@ -439,6 +515,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 ApplyExitCode(script, exitCode, LastMatchedLogTimestamp ?? UtcNowProvider(), CaptureLastMatchedProvenance());
             else if (ownerPolicyId != null)
                 _logger.Debug($"ImeLogTracker: exit code {exitCode} belongs to platform script {ownerPolicyId}, whose completion was already emitted — dropped");
+            else
+                LogLineBehindWriterBoundary($"exit code {exitCode}");
             // An exit code means the executor just wrote its end block and IME is about to
             // write the result — both land at a stale stream position when another process
             // appended meanwhile. Check the ledgers on the next pass.
@@ -465,17 +543,24 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         {
             var outputType = parameters != null && parameters.TryGetValue("outputType", out var ot) ? ot : null;
             var script = GetCurrentScriptForLineUpdate(parameters);
-            if (script == null) return;
+            if (script == null)
+            {
+                LogLineBehindWriterBoundary($"script output ({outputType ?? "combined"})");
+                return;
+            }
 
             // PS-AGENT-OUTPUT captures both stdout and stderr in one pattern
             var output = match.Groups["output"]?.Value;
-            var error = match.Groups["error"]?.Value;
+            var error = match.Groups["error"];
 
-            if (!string.IsNullOrEmpty(output) && !string.IsNullOrEmpty(error))
+            if (error != null && error.Success)
             {
-                // Combined pattern (write output done. output = ..., error = ...)
-                script.Stdout = TruncateOutput(output.Trim());
-                script.Stderr = TruncateOutput(error.Trim());
+                // Combined pattern (write output done. output = ..., error = ...): both texts as
+                // AgentExecutor wrote them to the result files — the error part is the error file
+                // IME judges. The "error from script" line before it is a snapshot taken before the
+                // output readers finished, so this one replaces it, an empty stdout included.
+                script.Stdout = TruncateOutput(output?.Trim());
+                script.Stderr = TruncateOutput(error.Value.Trim());
             }
             else if (string.Equals(outputType, "stderr", StringComparison.OrdinalIgnoreCase))
             {
@@ -507,7 +592,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
 
             if (string.IsNullOrEmpty(id)) return;
 
-            CompletePlatformScriptFromImeResult(id, result, LastMatchedLogTimestamp, LastMatchedPatternId, CaptureLastMatchedProvenance());
+            CompletePlatformScriptFromImeResult(id, result, LastMatchedLogTimestamp, LastMatchedPatternId, CaptureLastMatchedProvenance(), ImeUserIdFrom(match.Value));
         }
 
         /// <summary>
@@ -521,48 +606,46 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         /// line reopened the slot, produced a fallback duplicate (session e7f3c910).
         /// <see cref="FlushPendingPlatformScriptResults"/> emits the held completion.
         /// </summary>
-        internal void CompletePlatformScriptFromImeResult(string policyId, string result, DateTime? resultLineTimestampUtc, string patternId, CmTraceLineProvenance resultProvenance)
+        internal void CompletePlatformScriptFromImeResult(string policyId, string result, DateTime? resultLineTimestampUtc, string patternId, CmTraceLineProvenance resultProvenance, string userId = null)
         {
-            // Dedup: the deadline-based fallback (FlushPendingPlatformScriptResults) may already have
-            // emitted this script from its AgentExecutor exit code because IME's authoritative
-            // PS-SCRIPT-RESULT line arrived late. The fallback carries the same exit code + stdout,
-            // so re-emitting here would duplicate the timeline entry and inflate counts. Drop the
-            // now-redundant pending entry and skip.
-            if (_platformScriptResultEmitted.ContainsKey(policyId))
+            // The result belongs to the run of this policy that started last before its line —
+            // the run in flight, or an earlier one that waits for its result while a later run
+            // already started (ParkPlatformRun).
+            var script = FindRunForResult(policyId, userId, resultLineTimestampUtc);
+            if (script == null)
             {
-                _logger.Debug($"ImeLogTracker: platform script {policyId} PS-SCRIPT-RESULT arrived after fallback emit — skipping duplicate");
-                _pendingPlatformScripts.Remove(policyId);
-                return;
-            }
+                // Dedup: the deadline-based fallback (FlushPendingPlatformScriptResults) may already
+                // have emitted this run from its AgentExecutor end block because IME's authoritative
+                // PS-SCRIPT-RESULT line arrived late, or the same result line is read again.
+                // Re-emitting would duplicate the timeline entry and inflate counts.
+                if (_platformScriptResultEmitted.ContainsKey(policyId))
+                {
+                    _logger.Debug($"ImeLogTracker: platform script {policyId} PS-SCRIPT-RESULT arrived after its run was emitted — skipping duplicate");
+                    return;
+                }
 
-            // Merge with pending AgentExecutor data if available
-            if (_pendingPlatformScripts.TryGetValue(policyId, out var script))
-            {
-                // Stale-result guard: on an intra-lifetime re-run of the same policy, run 1's
-                // late PS-SCRIPT-RESULT can arrive after run 2's start line already created a
-                // fresh slot (the start clears the emitted-marker). Merging would pair run 2's
-                // StartedAtUtc/state with run 1's result and then drop run 2's genuine result at
-                // the marker check above. A result line always postdates its own run's start
-                // line in the source log, so a result older than the pending slot's start
-                // belongs to a previous run — drop it and keep the live slot intact.
-                if (script.StartedAtUtc.HasValue
-                    && resultLineTimestampUtc.HasValue
-                    && resultLineTimestampUtc.Value < script.StartedAtUtc.Value)
+                // Stale-result guard: every run of this policy in flight started after the result
+                // line — a result line always postdates its own run's start line in the source log,
+                // so it belongs to a previous run. Keep the live runs intact.
+                if (HasLivePlatformRun(policyId))
                 {
                     _logger.Debug($"ImeLogTracker: platform script {policyId} result predates the current run's start — stale result from a previous run, skipping");
                     return;
                 }
-            }
-            else
-            {
+
                 script = new ScriptExecutionState
                 {
                     PolicyId = policyId,
-                    ScriptType = "platform"
+                    ScriptType = "platform",
+                    UserId = userId,
+                    RunId = NewRunId(),
                 };
                 _pendingPlatformScripts[policyId] = script;
+                ScriptRuns.NoteStarted(userId, policyId, UtcNowProvider());
             }
 
+            if (script.UserId == null && userId != null) script.UserId = userId;
+            ResolveParkedRunsBefore(script);
             script.Result = result;
             script.ResultSource = "ime_policy_result";
             script.ResultObservedAtUtc = resultLineTimestampUtc ?? UtcNowProvider();
@@ -591,19 +674,150 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         private void EmitPlatformScriptResult(ScriptExecutionState script, string note = null)
         {
             _logger.Info($"ImeLogTracker: platform script completed: {script.PolicyId}, result={script.Result}, exit={script.ExitCode}{(note != null ? $" ({note})" : string.Empty)}");
+            if (string.IsNullOrEmpty(script.RunId)) script.RunId = NewRunId();
             EmitScriptEvent(script);
+            // The register keeps the latest run per (user, policy) for the registry reconciliation:
+            // a run that waited for its result while a later one started must not take that later
+            // run's entry.
+            if (!HasLaterLivePlatformRun(script)) ScriptRuns.NoteEmitted(script, UtcNowProvider());
             // The run's source stamp, capped at the clock: a result line cannot be read before it
             // was written, so a stamp ahead of the clock is a wrong zone assumption on that line
             // (a rewound result resolved in the reader's zone, session 4377911b: +1 h). Left
             // uncapped, the marker made the genuine NEXT run's start line read as a late line of
-            // this run and its result a duplicate.
+            // this run and its result a duplicate. Only ever raised: a run emitted after a later
+            // one must not move the reference back.
             var runStamp = script.ResultObservedAtUtc ?? script.ExitObservedAtUtc ?? UtcNowProvider();
             var nowUtc = UtcNowProvider();
-            _platformScriptResultEmitted[script.PolicyId] = runStamp > nowUtc ? nowUtc : runStamp;
-            _pendingPlatformScripts.Remove(script.PolicyId);
+            var stamp = runStamp > nowUtc ? nowUtc : runStamp;
+            if (!_platformScriptResultEmitted.TryGetValue(script.PolicyId, out var previousStamp) || stamp > previousStamp)
+                _platformScriptResultEmitted[script.PolicyId] = stamp;
+            if (_pendingPlatformScripts.TryGetValue(script.PolicyId, out var current) && ReferenceEquals(current, script))
+                _pendingPlatformScripts.Remove(script.PolicyId);
+            else
+                _parkedPlatformScripts.Remove(script);
             _stateDirty = true;
         }
 
+        private static string NewRunId() => Guid.NewGuid().ToString("D");
+
+        /// <summary>A run older than this by source time is from a previous enrollment, not a run in flight.</summary>
+        private static readonly TimeSpan StalePlatformRunAge = TimeSpan.FromHours(24);
+
+        private static bool SameUserOrUnknown(string a, string b)
+            => a == null || b == null || string.Equals(a, b, StringComparison.OrdinalIgnoreCase);
+
+        private static DateTime StartOf(ScriptExecutionState run) => run.StartedAtUtc ?? DateTime.MinValue;
+
+        /// <summary>The runs of a policy that are not emitted yet: the earlier ones waiting for their IME result, then the one in flight.</summary>
+        private IEnumerable<ScriptExecutionState> LivePlatformRuns(string policyId)
+        {
+            foreach (var run in _parkedPlatformScripts)
+            {
+                if (string.Equals(run.PolicyId, policyId, StringComparison.OrdinalIgnoreCase)) yield return run;
+            }
+            if (_pendingPlatformScripts.TryGetValue(policyId, out var current)) yield return current;
+        }
+
+        private bool HasLivePlatformRun(string policyId) => LivePlatformRuns(policyId).Any();
+
+        /// <summary>The live run a start marker names, or null once that run was emitted.</summary>
+        private ScriptExecutionState FindLivePlatformRun(string policyId, string runId)
+            => LivePlatformRuns(policyId).FirstOrDefault(r => string.Equals(r.RunId, runId, StringComparison.Ordinal));
+
+        private bool HasLaterLivePlatformRun(ScriptExecutionState script)
+            => LivePlatformRuns(script.PolicyId).Any(r => !ReferenceEquals(r, script)
+                && SameUserOrUnknown(r.UserId, script.UserId) && StartOf(r) > StartOf(script));
+
+        /// <summary>
+        /// The live run an IME result line belongs to: of the runs of its policy that started at or before the line,
+        /// the latest — one of the same IME user when there is one.
+        /// </summary>
+        private ScriptExecutionState FindRunForResult(string policyId, string userId, DateTime? resultLineTimestampUtc)
+        {
+            ScriptExecutionState sameUser = null, anyUser = null;
+            foreach (var run in LivePlatformRuns(policyId))
+            {
+                if (resultLineTimestampUtc.HasValue && run.StartedAtUtc.HasValue && run.StartedAtUtc.Value > resultLineTimestampUtc.Value) continue;
+                if (anyUser == null || StartOf(run) > StartOf(anyUser)) anyUser = run;
+                if (SameUserOrUnknown(run.UserId, userId) && (sameUser == null || StartOf(run) > StartOf(sameUser))) sameUser = run;
+            }
+            return sameUser ?? anyUser;
+        }
+
+        /// <summary>
+        /// Moves the run in flight aside when the next executor run of its policy starts: it keeps its own end block and
+        /// waits for its IME result (<see cref="FindRunForResult"/>), the exit-code fallback, or a later run's result.
+        /// </summary>
+        private void ParkPlatformRun(ScriptExecutionState run)
+        {
+            _pendingPlatformScripts.Remove(run.PolicyId);
+            _parkedPlatformScripts.Add(run);
+            _stateDirty = true;
+            if (_parkedPlatformScripts.Count > MaxParkedPlatformScripts)
+            {
+                var oldest = _parkedPlatformScripts.OrderBy(StartOf).First();
+                _logger.Warning($"ImeLogTracker: more than {MaxParkedPlatformScripts} platform runs wait for their IME result — resolving the oldest ({oldest.PolicyId}, started {oldest.StartedAtUtc:o}) now");
+                ResolveParkedRun(oldest, "too many runs waiting for their IME result");
+            }
+            _logger.Debug($"ImeLogTracker: platform script {run.PolicyId}: the next executor run started before IME's result of run {run.RunId} was read — that run keeps its end block and waits for its result");
+        }
+
+        /// <summary>
+        /// Results arrive in run order: a parked run of the same IME user that started before the run a result belongs to
+        /// gets none any more (its result line was lost) — it goes out now, ahead of the later run.
+        /// </summary>
+        private void ResolveParkedRunsBefore(ScriptExecutionState owner)
+        {
+            if (_parkedPlatformScripts.Count == 0 || !owner.StartedAtUtc.HasValue) return;
+            var earlier = _parkedPlatformScripts
+                .Where(r => !ReferenceEquals(r, owner)
+                    && string.Equals(r.PolicyId, owner.PolicyId, StringComparison.OrdinalIgnoreCase)
+                    && SameUserOrUnknown(r.UserId, owner.UserId)
+                    && r.StartedAtUtc.HasValue && r.StartedAtUtc.Value < owner.StartedAtUtc.Value)
+                .OrderBy(StartOf)
+                .ToList();
+            foreach (var run in earlier) ResolveParkedRun(run, "a later run of this policy got its IME result first");
+        }
+
+        /// <summary>A parked run that will not get its IME result: out with what it has, or dropped when it has nothing.</summary>
+        private void ResolveParkedRun(ScriptExecutionState run, string why)
+        {
+            if (run.Result != null)
+            {
+                EmitPlatformScriptResult(run, why);
+            }
+            else if (run.ExitCode.HasValue)
+            {
+                EmitFromExecutorEndBlock(run, why);
+            }
+            else
+            {
+                _parkedPlatformScripts.Remove(run);
+                _stateDirty = true;
+                _logger.Debug($"ImeLogTracker: platform script {run.PolicyId} run {run.RunId} has neither IME result nor executor end block — dropped ({why})");
+            }
+        }
+
+        /// <summary>
+        /// IME's own verdict from a run's end block: Success exactly when the error file was empty
+        /// (<c>IsNullOrEmpty(errorFile.Trim())</c> in IME), whatever the exit code — PowerShell returns 0 after a
+        /// non-terminating error and any code a script exits with. Only when the stderr line was never read does the
+        /// exit code stand in.
+        /// </summary>
+        internal static string ImeResultFromEndBlock(ScriptExecutionState script)
+        {
+            if (script.Stderr != null) return string.IsNullOrWhiteSpace(script.Stderr) ? "Success" : "Failed";
+            return script.ExitCode == 0 ? "Success" : "Failed";
+        }
+
+        private void EmitFromExecutorEndBlock(ScriptExecutionState script, string why)
+        {
+            script.Result = ImeResultFromEndBlock(script);
+            script.ResultSource = "agentexecutor_fallback";
+            var basis = script.Stderr == null ? $"exit code {script.ExitCode}, stderr not read" : script.Stderr.Trim().Length == 0 ? "empty stderr" : "stderr present";
+            EmitPlatformScriptResult(script, $"{why} — {script.Result} from the executor end block ({basis}) (fallback)");
+        }
+
         /// <summary>
         /// Grace period after a platform script's AgentExecutor exit code is observed before
         /// <see cref="FlushPendingPlatformScriptResults"/> emits a completion from that exit code.
@@ -641,29 +855,48 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         /// out once its executor end block has been read — the block arrives within one pass, so
         /// stdout/stderr are in by now — or after <see cref="PlatformScriptEndBlockGrace"/>.</item>
         /// <item>A script with a known AgentExecutor exit code but no IME <c>PS-SCRIPT-RESULT</c>
-        /// line within <see cref="PlatformScriptResultGrace"/> is emitted from the exit code
-        /// (0 → Success, else Failed), tagged <c>resultSource=agentexecutor_fallback</c> so the
-        /// data is honest about its provenance. Without this, scripts that completed shortly
-        /// before the agent terminates were silently dropped.</item>
+        /// line within <see cref="PlatformScriptResultGrace"/> is emitted from its end block by
+        /// IME's own rule (<see cref="ImeResultFromEndBlock"/>), tagged
+        /// <c>resultSource=agentexecutor_fallback</c> so the data is honest about its provenance.
+        /// Without this, scripts that completed shortly before the agent terminates were silently
+        /// dropped.</item>
         /// </list>
+        /// Parked runs go first, oldest first, so a policy's runs leave in run order; one without
+        /// result and end block keeps waiting — across a shutdown too — until a later run's result
+        /// resolves it or it is a day old.
         /// Runs on the single-threaded polling loop (no locking needed, same as the handlers).
         /// <paramref name="force"/> bypasses both grace checks for the final pass on shutdown.
         /// </summary>
         internal void FlushPendingPlatformScriptResults(DateTime nowUtc, bool force = false)
         {
-            if (_pendingPlatformScripts.Count == 0) return;
+            if (_pendingPlatformScripts.Count == 0 && _parkedPlatformScripts.Count == 0) return;
 
             var fallbackEmitted = false;
-            foreach (var script in _pendingPlatformScripts.Values.ToList())
+            foreach (var run in _parkedPlatformScripts.OrderBy(StartOf).ToList())
             {
-                // Already emitted by the authoritative path — just drop the stale buffer entry.
-                if (_platformScriptResultEmitted.ContainsKey(script.PolicyId))
+                if (run.Result != null)
                 {
-                    _pendingPlatformScripts.Remove(script.PolicyId);
-                    _stateDirty = true;
+                    if (run.ExitCode.HasValue || force || !run.ResultHeldSinceUtc.HasValue || nowUtc - run.ResultHeldSinceUtc.Value >= PlatformScriptEndBlockGrace)
+                        EmitPlatformScriptResult(run, run.ExitCode.HasValue ? "executor end block read after the result" : $"no executor end block within {PlatformScriptEndBlockGrace.TotalSeconds:F0}s");
                     continue;
                 }
+                if (run.ExitCode.HasValue)
+                {
+                    if (!force && (!run.ExitObservedAtUtc.HasValue || nowUtc - run.ExitObservedAtUtc.Value < PlatformScriptResultGrace)) continue;
+                    EmitFromExecutorEndBlock(run, $"result not seen within {PlatformScriptResultGrace.TotalSeconds:F0}s{(force ? ", shutdown flush" : string.Empty)}");
+                    fallbackEmitted = true;
+                    continue;
+                }
+                if (run.StartedAtUtc.HasValue && nowUtc - run.StartedAtUtc.Value > StalePlatformRunAge)
+                {
+                    _parkedPlatformScripts.Remove(run);
+                    _stateDirty = true;
+                    _logger.Debug($"ImeLogTracker: platform script {run.PolicyId} run {run.RunId} waited a day without IME result or executor end block — dropped");
+                }
+            }
 
+            foreach (var script in _pendingPlatformScripts.Values.ToList())
+            {
                 if (script.Result != null)
                 {
                     if (script.ExitCode.HasValue)
@@ -682,10 +915,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     if (nowUtc - script.ExitObservedAtUtc.Value < PlatformScriptResultGrace) continue;
                 }
 
-                script.Result = script.ExitCode.Value == 0 ? "Success" : "Failed";
-                script.ResultSource = "agentexecutor_fallback";
-                EmitPlatformScriptResult(script,
-                    $"result not seen within {PlatformScriptResultGrace.TotalSeconds:F0}s{(force ? ", shutdown flush" : string.Empty)} — emitted from AgentExecutor exit code {script.ExitCode.Value} (fallback)");
+                EmitFromExecutorEndBlock(script, $"result not seen within {PlatformScriptResultGrace.TotalSeconds:F0}s{(force ? ", shutdown flush" : string.Empty)}");
                 fallbackEmitted = true;
             }
 
@@ -697,7 +927,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         /// <summary>Test seam: inject a pending platform script as if AgentExecutor.log had reported
         /// its start + exit code, without an IME PS-SCRIPT-RESULT line.</summary>
         internal void SeedPendingPlatformScriptForTesting(string policyId, int? exitCode, DateTime? exitObservedAtUtc, string stdout = null, DateTime? startedAtUtc = null,
-            CmTraceLineProvenance startedAtProvenance = null, CmTraceLineProvenance exitProvenance = null)
+            CmTraceLineProvenance startedAtProvenance = null, CmTraceLineProvenance exitProvenance = null, string stderr = null)
         {
             // Mirrors a fresh execution start: a new run clears any prior emitted-marker (see
             // HandleScriptStarted) so re-runs of the same policy within one lifetime emit again.
@@ -706,9 +936,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             {
                 PolicyId = policyId,
                 ScriptType = "platform",
+                RunId = NewRunId(),
                 ExitCode = exitCode,
                 ExitObservedAtUtc = exitObservedAtUtc,
                 Stdout = stdout,
+                Stderr = stderr,
                 StartedAtUtc = startedAtUtc,
                 StartedAtProvenance = startedAtProvenance,
                 ExitProvenance = exitProvenance,
@@ -717,6 +949,9 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             RecordInvocationMarker(policyId, isClose: false);
         }
 
+        /// <summary>Test seam: earlier runs waiting for their IME result while a later run of their policy is in flight.</summary>
+        internal int ParkedPlatformScriptCountForTest => _parkedPlatformScripts.Count;
+
         /// <summary>Test seam: the authoritative IME PS-SCRIPT-RESULT path for a platform script
         /// (the production handler minus regex extraction). <paramref name="resultLineTimestampUtc"/>
         /// stands in for the CMTrace timestamp of the PS-SCRIPT-RESULT line (production reads it
@@ -1163,11 +1398,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         internal static readonly TimeSpan HeldScriptStartGrace = TimeSpan.FromMinutes(30);
         internal static readonly TimeSpan HeldScriptStartShutdownGrace = TimeSpan.FromMinutes(5);
 
-        private static string TruncateOutput(string output)
+        internal static string TruncateOutput(string output)
         {
             if (string.IsNullOrEmpty(output) || output.Length <= MaxScriptOutputLength)
                 return output;
-            return output.Substring(0, MaxScriptOutputLength) + "...[truncated]";
+            return output.Substring(0, MaxScriptOutputLength) + OutputTruncationMarker;
         }
 
         // -----------------------------------------------------------------------

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ImeLogTracker.LogProcessing.cs

@@ -123,16 +123,19 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             var ledger = IsMultiWriterLogFile(fileName) ? GetLedger(fileName) : null;
 
             // Set by a rewind: entries that still read unchanged behind the old bookmark are
-            // skipped, and nothing below the old bookmark is fresh or a calibration anchor.
-            HashSet<LedgerEntry> rewoundEntries = null;
+            // skipped (their invocation markers are given back); a changed entry below the old
+            // bookmark is fresh only when the bytes it replaced were seen moments ago, and never a
+            // calibration anchor.
+            RewindState rewind = null;
             long oldBookmark = -1;
+            var writerBoundaries = IsWriterBoundaryLogFile(fileName);
 
             if (ledger != null)
             {
                 var rewindTo = await PrepareLedgerAsync(filePath, fileName, ledger, startPos, passNowUtc, token);
                 if (rewindTo >= 0)
                 {
-                    rewoundEntries = ApplyRewind(filePath, fileName, ledger, rewindTo, startPos);
+                    rewind = ApplyRewind(filePath, fileName, ledger, rewindTo, startPos);
                     oldBookmark = startPos;
                     startPos = rewindTo;
                 }
@@ -164,21 +167,21 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             {
                 // Guard zone: the file grew and is open anyway — re-check the entries just behind
                 // the bookmark, where a stale writer's block lands when it is short.
-                if (ledger != null && rewoundEntries == null && ledger.Entries.Count > 0)
+                if (ledger != null && rewind == null && ledger.Entries.Count > 0)
                 {
                     var guardFrom = ledger.OffsetOfEntryAtOrAfter(startPos - OverwriteGuardBytes);
                     if (guardFrom >= 0 && guardFrom < startPos)
                     {
-                        var divergence = await FindOverwriteAsync(stream, ledger, guardFrom, startPos, token);
+                        var divergence = await FindOverwriteAsync(stream, ledger, guardFrom, startPos, passNowUtc, token);
                         _verifiedBytes += startPos - guardFrom;
                         if (divergence >= 0)
                         {
                             // The guard saw only the tail of the ledger; the block may start earlier.
-                            var earliest = await FindOverwriteAsync(stream, ledger, ledger.StartOffset, startPos, token);
+                            var earliest = await FindOverwriteAsync(stream, ledger, ledger.StartOffset, startPos, passNowUtc, token);
                             _verifiedBytes += startPos - ledger.StartOffset;
                             _verifyPasses++;
                             if (earliest >= 0) divergence = earliest;
-                            rewoundEntries = ApplyRewind(filePath, fileName, ledger, divergence, startPos);
+                            rewind = ApplyRewind(filePath, fileName, ledger, divergence, startPos);
                             oldBookmark = startPos;
                             startPos = divergence;
                         }
@@ -259,7 +262,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                         // A fragment right at the bookmark of a multi-writer file (the previous
                         // entry ended exactly here, this one does not open an entry) is the tail of
                         // a block a stale writer laid over already-read bytes: verify before reading on.
-                        if (ledger != null && rewoundEntries == null && entry.Offset == ledger.EndOffset
+                        if (ledger != null && rewind == null && entry.Offset == ledger.EndOffset
                             && ledger.LastFragmentOffset != entry.Offset && !entry.Text.StartsWith("<![LOG["))
                         {
                             ledger.VerifyRequested = true;
@@ -269,11 +272,27 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                         }
                     }
 
-                    if (ledger != null) ledger.Record(entry);
-                    if (rewoundEntries != null && rewoundEntries.Contains(new LedgerEntry { Offset = entry.Offset, Hash = entry.Hash }))
-                        continue; // unchanged behind the old bookmark — processed before the rewind
+                    if (ledger != null) ledger.Record(entry, passNowUtc);
+                    var unchanged = rewind != null && rewind.IsUnchanged(entry);
+                    if (unchanged) RestoreInvocationMarkers(rewind, entry.Offset);
 
-                    _currentPassLinesAreFresh = passLinesAreFresh && entry.Offset >= oldBookmark;
+                    // Writer boundary (see ImeLogTracker.Overwrite.cs): an AgentExecutor.log entry that is
+                    // not exactly one CMTrace record ends the bytes of the executor in front of it. Never
+                    // matched — its text is the cut of two writers. Evaluated for unchanged entries too:
+                    // what owns the position in front of them may have changed with the rewind.
+                    if (writerBoundaries && !IsSingleCmTraceRecord(entry.Text))
+                    {
+                        CloseAtWriterBoundary(fileName, entry.Offset, entry.Text);
+                        continue;
+                    }
+
+                    if (unchanged) continue; // unchanged behind the old bookmark — processed before the rewind
+
+                    // Behind the old bookmark only changed entries arrive here: fresh when the bytes they replaced
+                    // were seen moments ago (RewoundEntryIsFresh), never a calibration anchor.
+                    _currentPassLinesAreFresh = entry.Offset >= oldBookmark
+                        ? passLinesAreFresh
+                        : rewind != null && RewoundEntryIsFresh(passLinesAreFresh, rewind.EntryAtRewindPointReplaced, rewind.OldestReplacedSeenUtc, passNowUtc);
 
                     // --- Normal processing (single-line or completed multiline) ---
                     CmTraceLogEntry parsed;

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ImeLogTracker.Overwrite.cs

@@ -62,6 +62,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             public long Offset;
             public int Length;
             public ulong Hash;
+            /// <summary>
+            /// When these bytes were last seen as they are (read, seeded or verified unchanged): bytes found different
+            /// at this position later were written after it. Not part of the identity.
+            /// </summary>
+            public DateTime SeenUtc;
 
             // Identity is (offset, hash): a tail first read unterminated and later completed
             // keeps its hash but grows by its terminator.
@@ -100,11 +105,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 return idx < Entries.Count ? Entries[idx].Offset : -1;
             }
 
-            public void Record(AssembledEntry e)
+            public void Record(AssembledEntry e, DateTime seenUtc)
             {
                 var idx = IndexOfFirstAtOrAfter(e.Offset);
                 if (idx < Entries.Count) Entries.RemoveRange(idx, Entries.Count - idx);
-                Entries.Add(new LedgerEntry { Offset = e.Offset, Length = e.Length, Hash = e.Hash });
+                Entries.Add(new LedgerEntry { Offset = e.Offset, Length = e.Length, Hash = e.Hash, SeenUtc = seenUtc });
             }
 
             /// <summary>Drops everything from <paramref name="offset"/> on and returns it — the entries a rewind must not process twice.</summary>
@@ -197,7 +202,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             {
                 ledger.Seeded = true;
                 if (ledger.Entries.Count == 0 && bookmark > 0)
-                    await SeedLedgerAsync(filePath, ledger, bookmark, token).ConfigureAwait(false);
+                    await SeedLedgerAsync(filePath, ledger, bookmark, nowUtc, token).ConfigureAwait(false);
             }
 
             var due = ledger.VerifyRequested || (InContention(nowUtc) && nowUtc >= ledger.NextCadenceVerifyUtc);
@@ -213,7 +218,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
 
             long divergence;
             using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
-                divergence = await FindOverwriteAsync(stream, ledger, from, bookmark, token).ConfigureAwait(false);
+                divergence = await FindOverwriteAsync(stream, ledger, from, bookmark, nowUtc, token).ConfigureAwait(false);
             if (token.IsCancellationRequested) return -1;
 
             ledger.VerifyRequested = false;
@@ -228,8 +233,9 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         /// Re-reads [fromOffset, toOffset) with the read loop's assembler and compares against the
         /// ledger. Returns the offset of the first entry whose bytes changed — a ledger entry not
         /// reproduced, or an entry the ledger never had — or -1 when everything reads as before.
+        /// Every entry found unchanged is stamped seen at <paramref name="nowUtc"/>.
         /// </summary>
-        private async Task<long> FindOverwriteAsync(FileStream stream, FileLedger ledger, long fromOffset, long toOffset, CancellationToken token)
+        private async Task<long> FindOverwriteAsync(FileStream stream, FileLedger ledger, long fromOffset, long toOffset, DateTime nowUtc, CancellationToken token)
         {
             var entries = ledger.Entries;
             var idx = ledger.IndexOfFirstAtOrAfter(fromOffset);
@@ -255,6 +261,9 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 if (idx < entries.Count && entries[idx].Offset == e.Offset)
                 {
                     if (entries[idx].Hash != e.Hash) return e.Offset;
+                    var confirmed = entries[idx];
+                    confirmed.SeenUtc = nowUtc;
+                    entries[idx] = confirmed;
                     idx++;
                     continue;
                 }
@@ -265,7 +274,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         }
 
         /// <summary>After a restart the ledger is empty: fingerprint the entries just behind the persisted bookmark without processing them.</summary>
-        private async Task SeedLedgerAsync(string filePath, FileLedger ledger, long bookmark, CancellationToken token)
+        private async Task SeedLedgerAsync(string filePath, FileLedger ledger, long bookmark, DateTime nowUtc, CancellationToken token)
         {
             var from = Math.Max(0, bookmark - RestartSeedBytes);
             using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
@@ -288,18 +297,69 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     if (assembler.Feed(line, reader.LastLineStart, reader.Position, reader.LastLineTruncated, reader.LastLineHash, out e)
                             == CmTraceEntryAssembler.Outcome.Entry
                         && e.Offset + e.Length <= bookmark)
-                        ledger.Record(e);
+                        ledger.Record(e, nowUtc);
                 }
             }
         }
 
-        /// <summary>Moves the bookmark back to the first changed entry; returns the entries to skip if they still read unchanged behind it.</summary>
-        private HashSet<LedgerEntry> ApplyRewind(string filePath, string fileName, FileLedger ledger, long rewindTo, long bookmark)
+        /// <summary>
+        /// What one rewind pass carries: the entries to skip if they still read unchanged behind the rewind point, and
+        /// the invocation markers set aside there until their entries prove unchanged. Pass-local by design — whatever
+        /// is not given back dies with the pass on every exit path.
+        /// </summary>
+        private sealed class RewindState
+        {
+            public RewindState(string fileName, HashSet<LedgerEntry> unchanged, List<InvocationMarker> markers, InvocationMarker lastPlatformMarker, long rewindTo)
+            {
+                FileName = fileName;
+                Unchanged = unchanged;
+                Markers = markers;
+                LastPlatformMarker = lastPlatformMarker;
+                foreach (var replaced in unchanged)
+                {
+                    if (replaced.Offset == rewindTo) EntryAtRewindPointReplaced = true;
+                    if (!OldestReplacedSeenUtc.HasValue || replaced.SeenUtc < OldestReplacedSeenUtc.Value) OldestReplacedSeenUtc = replaced.SeenUtc;
+                }
+            }
+
+            public string FileName { get; }
+            public HashSet<LedgerEntry> Unchanged { get; }
+            /// <summary>Set aside at the rewind, ascending by offset.</summary>
+            public List<InvocationMarker> Markers { get; }
+            /// <summary>The tracker-wide last platform marker, when it was among the set-aside ones.</summary>
+            public InvocationMarker LastPlatformMarker { get; }
+            public int Next { get; set; }
+            /// <summary>The ledger held the entry at the rewind point: the changed bytes lie where something was seen before.</summary>
+            public bool EntryAtRewindPointReplaced { get; }
+            /// <summary>The earliest time any of the replaced bytes was last seen as it was: every changed byte was written after it.</summary>
+            public DateTime? OldestReplacedSeenUtc { get; }
+
+            public bool IsUnchanged(AssembledEntry entry) => Unchanged.Contains(new LedgerEntry { Offset = entry.Offset, Hash = entry.Hash });
+        }
+
+        /// <summary>
+        /// Whether an entry a rewind re-processes (it reads differently than before) is fresh. Its bytes were written after
+        /// the bytes it replaced were last seen as they were — IME stamps a line when it writes it — so when that was at
+        /// most <see cref="FreshLineMaxAge"/> ago the entry's age is bounded like an appended line's and it may anchor
+        /// itself (session d29e27e3: recovered result lines fell back to the agent's stale zone and lost their duration).
+        /// Not fresh when the pass is not (the first pass after a restart never anchors), when the divergence lies in bytes
+        /// the ledger never held (nothing dates them), or when the clock stepped back since.
+        /// </summary>
+        internal static bool RewoundEntryIsFresh(bool passLinesAreFresh, bool entryAtRewindPointReplaced, DateTime? oldestReplacedSeenUtc, DateTime passNowUtc)
+        {
+            if (!passLinesAreFresh || !entryAtRewindPointReplaced || !oldestReplacedSeenUtc.HasValue) return false;
+            var sinceSeen = passNowUtc - oldestReplacedSeenUtc.Value;
+            return sinceSeen >= TimeSpan.Zero && sinceSeen <= FreshLineMaxAge;
+        }
+
+        /// <summary>Moves the bookmark back to the first changed entry; returns what the re-read needs to skip and to give back.</summary>
+        private RewindState ApplyRewind(string filePath, string fileName, FileLedger ledger, long rewindTo, long bookmark)
         {
             var removed = ledger.TruncateFrom(rewindTo);
             _positionTracker.SetPosition(filePath, rewindTo);
             _heldTails.Remove(filePath);
-            InvalidateInvocationMarkersFrom(fileName, rewindTo);
+            var lastPlatformMarker = _lastPlatformMarker;
+            var markers = TakeInvocationMarkersFrom(fileName, rewindTo, out var tookLastPlatformMarker);
             _overwriteRewinds++;
             _overwriteBytesReprocessed += bookmark - rewindTo;
 
@@ -314,7 +374,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             {
                 _logger.Debug(message);
             }
-            return removed;
+            return new RewindState(fileName, removed, markers, tookLastPlatformMarker ? lastPlatformMarker : null, rewindTo);
         }
 
         private long RetentionFloor(string fileName, long bookmark)
@@ -331,20 +391,44 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         // -----------------------------------------------------------------------
         //
         // AgentExecutor.log carries "Powershell exit code is N" / "write output done" without a
-        // policy id. Their owner is decided by FILE POSITION, not by the order lines were read:
-        // an executor writes its end block at its own stream position, i.e. directly after its
-        // own start block in the final bytes, so the nearest preceding invocation marker names
-        // it — and stays right after a rewind re-reads that region. A marker is a platform start
-        // (policy id), some other invocation (detection, remediation, requirement: null) or a
-        // close ("gets invoked" banner, "Agent executor completed").
+        // policy id. Their owner is decided by FILE POSITION: the nearest preceding marker — a
+        // platform start (policy id), some other invocation (detection, remediation, requirement:
+        // null), a close ("gets invoked" banner, "Agent executor completed") or a writer boundary.
+        //
+        // Every executor writes its lines contiguously from its own stream position, so its end
+        // block follows its own start block — but that start block may be gone. Two executors that
+        // open the file at the same end write their start blocks over each other, and the end block
+        // of the one that lost then sits behind the OTHER executor's start block (session 756970cf:
+        // a detection script's exit code and output on a platform script). Where one writer's bytes
+        // meet another's, the cut leaves an entry that is not exactly one CMTrace record — a
+        // fragment, a merged line or an empty line — unless the line boundaries of both writers
+        // coincide byte-exactly. That writer boundary closes the platform invocation in front of it.
+        // AgentExecutor.log only: in the IME log the service writes the markers and the lines they
+        // own itself, and its fragments are executor telemetry lines.
+        //
+        // A marker lives exactly as long as the bytes of its entry: a rewind sets the markers from
+        // the rewind point on aside, and an entry that reads unchanged gets its markers back.
 
         private sealed class InvocationMarker
         {
             public long Offset;
             public string PolicyId;
+            /// <summary>
+            /// The platform run the start line belongs to: the lines behind it go to that run while it is pending or
+            /// waits for its IME result, and nowhere once it was emitted — never to a later run of the same policy.
+            /// Null only on seeded test markers, which resolve by policy.
+            /// </summary>
+            public string RunId;
             public bool IsClose;
+            /// <summary>Set on a writer boundary: the platform invocation it closed.</summary>
+            public string ClosedPolicyId;
         }
 
+        /// <summary>Run id of a start line whose run was emitted already (a late line): owns its lines, matches no live run.</summary>
+        private const string EmittedRunId = "emitted";
+
+        private const string ExecutorLogFileName = "AgentExecutor.log";
+
         private readonly Dictionary<string, List<InvocationMarker>> _invocationMarkers =
             new Dictionary<string, List<InvocationMarker>>(StringComparer.OrdinalIgnoreCase);
         private InvocationMarker _lastPlatformMarker;
@@ -354,24 +438,62 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         private readonly HashSet<string> _platformMarkerFiles = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
         private long _testEntryOrdinal;
 
-        private void RecordInvocationMarker(string policyId, bool isClose)
+        /// <summary>
+        /// The executor log, live or rotated (<c>AgentExecutor-yyyyMMdd-HHmmss.log</c>): its invocations are one process
+        /// each, so a writer boundary ends an invocation — in the final bytes of a rotation as much as in the live file.
+        /// </summary>
+        internal static bool IsWriterBoundaryLogFile(string fileName)
+            => string.Equals(fileName, ExecutorLogFileName, StringComparison.OrdinalIgnoreCase)
+            || (fileName != null
+                && fileName.StartsWith("AgentExecutor-", StringComparison.OrdinalIgnoreCase)
+                && fileName.EndsWith(".log", StringComparison.OrdinalIgnoreCase));
+
+        /// <summary>
+        /// True when the entry is exactly one CMTrace record: it opens with <c>&lt;![LOG[</c> (culture-sensitive like
+        /// <c>CmTraceLogParser.TryParseLine</c>, so a BOM is ignorable) and holds no second one — the parser takes the
+        /// message up to the LAST trailer, so a line cut anywhere, its trailer included, would swallow the record
+        /// written over it. An empty entry is the terminator of a cut line. A script whose own output contains the
+        /// open tag loses that output line: the bytes cannot tell it from a merged line.
+        /// </summary>
+        internal static bool IsSingleCmTraceRecord(string text)
+        {
+            if (string.IsNullOrEmpty(text) || !text.StartsWith(LogOpenTag)) return false;
+            var first = text.IndexOf(LogOpenTag, StringComparison.Ordinal);
+            return first >= 0 && text.IndexOf(LogOpenTag, first + LogOpenTag.Length, StringComparison.Ordinal) < 0;
+        }
+
+        private List<InvocationMarker> GetOrCreateMarkerList(string file)
         {
-            if (_currentEntryOffset < 0) return;
-            var file = _currentSourceFileName ?? TestSourceFileName;
             List<InvocationMarker> list;
             if (!_invocationMarkers.TryGetValue(file, out list))
             {
                 list = new List<InvocationMarker>();
                 _invocationMarkers[file] = list;
             }
+            return list;
+        }
+
+        private static void AppendInvocationMarker(List<InvocationMarker> list, InvocationMarker marker)
+        {
+            if (list.Count >= MaxInvocationMarkersPerFile) list.RemoveAt(0);
+            list.Add(marker);
+        }
+
+        private void RecordInvocationMarker(string policyId, bool isClose, string runId = null)
+        {
+            if (_currentEntryOffset < 0) return;
+            var file = _currentSourceFileName ?? TestSourceFileName;
+            var list = GetOrCreateMarkerList(file);
 
             if (list.Count > 0 && list[list.Count - 1].Offset == _currentEntryOffset)
             {
                 // Two patterns on one line: the platform start outranks the generic argument line.
+                // A writer boundary is never upgraded.
                 var last = list[list.Count - 1];
-                if (!isClose && policyId != null)
+                if (!isClose && policyId != null && last.ClosedPolicyId == null)
                 {
                     last.PolicyId = policyId;
+                    last.RunId = runId;
                     last.IsClose = false;
                     _lastPlatformMarker = last;
                     _platformMarkerFiles.Add(file);
@@ -379,9 +501,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 return;
             }
 
-            if (list.Count >= MaxInvocationMarkersPerFile) list.RemoveAt(0);
-            var marker = new InvocationMarker { Offset = _currentEntryOffset, PolicyId = policyId, IsClose = isClose };
-            list.Add(marker);
+            var marker = new InvocationMarker { Offset = _currentEntryOffset, PolicyId = policyId, RunId = runId, IsClose = isClose };
+            AppendInvocationMarker(list, marker);
             if (!isClose && policyId != null)
             {
                 _lastPlatformMarker = marker;
@@ -390,21 +511,34 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         }
 
         /// <summary>
-        /// The pending platform script that owns the entry being processed, or null.
-        /// <paramref name="ownerPolicyId"/> names the owning platform script even when its slot is
-        /// gone (completion already emitted); null when no platform invocation owns the entry.
+        /// An entry of <paramref name="fileName"/> at <paramref name="offset"/> that is not exactly one CMTrace record:
+        /// the bytes behind it were written by another process than the bytes in front of it. Closes the platform
+        /// invocation that owns the position; records nothing when none is open there (a cut multi-line output yields
+        /// one fragment per line). Idempotent at the same offset.
         /// </summary>
-        private ScriptExecutionState ResolvePlatformScriptForCurrentEntry(out string ownerPolicyId)
+        private void CloseAtWriterBoundary(string fileName, long offset, string text)
+        {
+            var owner = FindOwningMarker(fileName, offset);
+            if (owner == null || owner.IsClose || owner.PolicyId == null) return;
+
+            var list = GetOrCreateMarkerList(fileName);
+            if (list.Count > 0 && list[list.Count - 1].Offset >= offset) return;
+            AppendInvocationMarker(list, new InvocationMarker { Offset = offset, IsClose = true, ClosedPolicyId = owner.PolicyId });
+
+            var kind = string.IsNullOrEmpty(text) ? "empty line" : text.StartsWith(LogOpenTag) ? "merged line" : "fragment";
+            _logger.Debug($"ImeLogTracker: writer boundary in {fileName} at offset {offset} ({kind}, {text?.Length ?? 0} chars) closes platform script {owner.PolicyId} (opened at {owner.Offset}) — the bytes behind it belong to another executor");
+        }
+
+        /// <summary>The marker that owns <paramref name="offset"/> in <paramref name="file"/>, or null.</summary>
+        private InvocationMarker FindOwningMarker(string file, long offset)
         {
-            ownerPolicyId = null;
-            var file = _currentSourceFileName ?? TestSourceFileName;
             InvocationMarker marker = null;
             List<InvocationMarker> list = null;
-            if (_currentEntryOffset >= 0 && _invocationMarkers.TryGetValue(file, out list))
+            if (offset >= 0 && _invocationMarkers.TryGetValue(file, out list))
             {
                 for (var i = list.Count - 1; i >= 0; i--)
                 {
-                    if (list[i].Offset <= _currentEntryOffset)
+                    if (list[i].Offset <= offset)
                     {
                         marker = list[i];
                         break;
@@ -420,24 +554,52 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             // (session 24dc69d1: the health-script worker's exit line pre-filled a platform slot's
             // exit code, its launch line the slot's context).
             if (marker == null && (list == null || list.Count == 0) && _platformMarkerFiles.Contains(file)) marker = _lastPlatformMarker;
+            return marker;
+        }
+
+        /// <summary>
+        /// The pending platform script that owns the entry being processed, or null.
+        /// <paramref name="ownerPolicyId"/> names the owning platform script even when its slot is
+        /// gone (completion already emitted); null when no platform invocation owns the entry.
+        /// </summary>
+        private ScriptExecutionState ResolvePlatformScriptForCurrentEntry(out string ownerPolicyId)
+        {
+            ownerPolicyId = null;
+            var marker = FindOwningMarker(_currentSourceFileName ?? TestSourceFileName, _currentEntryOffset);
             if (marker == null || marker.IsClose || marker.PolicyId == null) return null;
 
             ownerPolicyId = marker.PolicyId;
+            if (marker.RunId != null) return FindLivePlatformRun(marker.PolicyId, marker.RunId);
             ScriptExecutionState state;
             return _pendingPlatformScripts.TryGetValue(marker.PolicyId, out state) ? state : null;
         }
 
-        private void InvalidateInvocationMarkersFrom(string fileName, long offset)
+        /// <summary>Debug trace for an executor line that a writer boundary kept away from a platform script.</summary>
+        private void LogLineBehindWriterBoundary(string what)
         {
+            var marker = FindOwningMarker(_currentSourceFileName ?? TestSourceFileName, _currentEntryOffset);
+            if (marker?.ClosedPolicyId == null) return;
+            _logger.Debug($"ImeLogTracker: {what} at offset {_currentEntryOffset} lies behind the writer boundary at {marker.Offset} that closed platform script {marker.ClosedPolicyId} — another executor's end block, not attributed");
+        }
+
+        /// <summary>Removes the markers from <paramref name="offset"/> on and returns them in offset order.</summary>
+        private List<InvocationMarker> TakeInvocationMarkersFrom(string fileName, long offset, out bool tookLastPlatformMarker)
+        {
+            tookLastPlatformMarker = false;
+            var taken = new List<InvocationMarker>();
             List<InvocationMarker> list;
-            if (!_invocationMarkers.TryGetValue(fileName, out list) || list.Count == 0) return;
-            var removedLast = false;
-            for (var i = list.Count - 1; i >= 0 && list[i].Offset >= offset; i--)
+            if (!_invocationMarkers.TryGetValue(fileName, out list) || list.Count == 0) return taken;
+
+            var from = list.Count;
+            while (from > 0 && list[from - 1].Offset >= offset) from--;
+            for (var i = from; i < list.Count; i++)
             {
-                if (ReferenceEquals(list[i], _lastPlatformMarker)) removedLast = true;
-                list.RemoveAt(i);
+                if (ReferenceEquals(list[i], _lastPlatformMarker)) tookLastPlatformMarker = true;
+                taken.Add(list[i]);
             }
-            if (removedLast)
+            list.RemoveRange(from, list.Count - from);
+
+            if (tookLastPlatformMarker)
             {
                 _lastPlatformMarker = null;
                 for (var i = list.Count - 1; i >= 0; i--)
@@ -449,6 +611,28 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     }
                 }
             }
+            return taken;
+        }
+
+        private void InvalidateInvocationMarkersFrom(string fileName, long offset) => TakeInvocationMarkersFrom(fileName, offset, out _);
+
+        /// <summary>
+        /// An entry that reads unchanged after a rewind keeps its markers: gives back the set-aside markers at exactly
+        /// <paramref name="entryOffset"/>. Set-aside markers in front of it belonged to entries that changed and stay
+        /// gone with their bytes.
+        /// </summary>
+        private void RestoreInvocationMarkers(RewindState rewind, long entryOffset)
+        {
+            var markers = rewind.Markers;
+            while (rewind.Next < markers.Count && markers[rewind.Next].Offset < entryOffset) rewind.Next++;
+            while (rewind.Next < markers.Count && markers[rewind.Next].Offset == entryOffset)
+            {
+                var marker = markers[rewind.Next++];
+                var list = GetOrCreateMarkerList(rewind.FileName);
+                if (list.Count > 0 && list[list.Count - 1].Offset >= marker.Offset) continue;
+                AppendInvocationMarker(list, marker);
+                if (ReferenceEquals(marker, rewind.LastPlatformMarker)) _lastPlatformMarker = marker;
+            }
         }
 
         private long OldestPendingScriptMarkerOffset(string fileName)
@@ -474,6 +658,9 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         /// <summary>What a rollover of the file does to its invocation markers.</summary>
         internal void ClearInvocationMarkersForTest(string fileName) => InvalidateInvocationMarkersFrom(fileName, 0);
 
+        internal int InvocationMarkerCountForTest(string fileName)
+            => _invocationMarkers.TryGetValue(fileName, out var list) ? list.Count : 0;
+
         internal int LedgerEntryCountForTest(string fileName)
         {
             FileLedger ledger;

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ImeLogTracker.cs

@@ -182,6 +182,19 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         private readonly Dictionary<string, ScriptExecutionState> _pendingPlatformScripts =
             new Dictionary<string, ScriptExecutionState>(StringComparer.OrdinalIgnoreCase);
 
+        // Earlier runs of a policy whose next executor run started before IME's result of them was
+        // read (IME re-runs a failed script on later check-ins; the first pass reads all of
+        // AgentExecutor.log before the IME log). Each keeps its own end block until its result
+        // arrives — session eff1b413 lost that and paired the first result with the last run's block.
+        private readonly List<ScriptExecutionState> _parkedPlatformScripts = new List<ScriptExecutionState>();
+        private const int MaxParkedPlatformScripts = 64;
+
+        /// <summary>
+        /// The platform runs this tracker started and emitted, for the registry reconciliation that
+        /// checks them against IME's saved results (D-316). Shared with the registry host's thread.
+        /// </summary>
+        internal PlatformScriptRunRegister ScriptRuns { get; } = new PlatformScriptRunRegister();
+
         // Health-script (remediation) line-by-line accumulator — single slot because IME
         // executes health scripts SEQUENTIALLY within a session (verified across multiple
         // diagnostic captures: ProcessScript → context → exit → stdout → stderr → compliance,
@@ -240,7 +253,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         // the 32K-char Table Storage property limit that bounds the event downstream. Growth
         // driver is the number of log lines the bootstrap chain writes, so re-measure before
         // adding a chatty step rather than raising this again.
-        private const int MaxScriptOutputLength = 8192;
+        internal const int MaxScriptOutputLength = 8192;
+        internal const string OutputTruncationMarker = "...[truncated]";
         private const int MaxMultiLineBufferLines = 100;
         // Size cap for ONE entry — a single physical line (enforced by BoundedLineReader before
         // the line is materialized) and an assembled multiline entry alike. Any process able to
@@ -389,6 +403,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     VerifiedBytes = _verifiedBytes,
                     PassMaxMs = _passMaxMs,
                     PassGapMaxMs = _passGapMaxMs,
+                    PlatformOutputVerified = ScriptRuns.Verified,
+                    PlatformOutputCorrected = ScriptRuns.Corrected,
                     PatternHits = new Dictionary<string, int>(_patternHits, StringComparer.OrdinalIgnoreCase),
                 };
             }
@@ -1034,6 +1050,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         internal async Task RunPollPassAsync(CancellationToken token)
         {
             var startMs = MonotonicMillisProvider();
+            var passStartedUtc = UtcNowProvider();
             if (_lastPassEndMs >= 0 && startMs - _lastPassEndMs > _passGapMaxMs)
             {
                 _passGapMaxMs = startMs - _lastPassEndMs;
@@ -1045,6 +1062,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
             FlushRecurringScripts(UtcNowProvider(), shuttingDown: false);
             CheckPendingTokenFailure(UtcNowProvider());
 
+            // The lines written before this pass started are read now — a held tail or a fragment
+            // awaiting its check follows a pass or two later, which TrackerCatchUp covers. The
+            // registry reconciliation waits for such a pass before it pairs an IME save with a run.
+            if (!token.IsCancellationRequested) ScriptRuns.NotePassCompleted(passStartedUtc);
+            if (ScriptRuns.ConsumeCountersChanged()) _stateDirty = true;
+
             var endMs = MonotonicMillisProvider();
             if (endMs - startMs > _passMaxMs)
             {
@@ -1175,6 +1198,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 }
             }
 
+            _parkedPlatformScripts.Clear();
+            if (state.ParkedPlatformScripts != null)
+            {
+                foreach (var parked in state.ParkedPlatformScripts)
+                {
+                    if (!string.IsNullOrEmpty(parked?.PolicyId) && _parkedPlatformScripts.Count < MaxParkedPlatformScripts)
+                        _parkedPlatformScripts.Add(parked);
+                }
+            }
+
             _scriptTimeoutSuspectedPosted.Clear();
             if (state.ScriptTimeoutSuspectedPosted != null)
             {
@@ -1207,6 +1240,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     _verifiedBytes = state.Health.VerifiedBytes;
                     _passMaxMs = state.Health.PassMaxMs;
                     _passGapMaxMs = state.Health.PassGapMaxMs;
+                    ScriptRuns.RestoreCounters(state.Health.PlatformOutputVerified, state.Health.PlatformOutputCorrected);
                 }
                 if (state.PatternHits != null)
                 {
@@ -1259,6 +1293,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                 // must survive restarts — see the LoadState comment for the duplicate scenario.
                 PlatformScriptResultEmittedAt = new Dictionary<string, DateTime>(_platformScriptResultEmitted, StringComparer.OrdinalIgnoreCase),
                 PendingPlatformScripts = _pendingPlatformScripts.Values.ToList(),
+                ParkedPlatformScripts = _parkedPlatformScripts.ToList(),
                 ScriptTimeoutSuspectedPosted = _scriptTimeoutSuspectedPosted.ToList(),
                 RecurringScripts = _recurringScripts.ToPersisted(),
             };
@@ -1283,6 +1318,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
                     VerifiedBytes = _verifiedBytes,
                     PassMaxMs = _passMaxMs,
                     PassGapMaxMs = _passGapMaxMs,
+                    PlatformOutputVerified = ScriptRuns.Verified,
+                    PlatformOutputCorrected = ScriptRuns.Corrected,
                 };
                 state.PatternHits = new Dictionary<string, int>(_patternHits, StringComparer.OrdinalIgnoreCase);
             }

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ImeTrackerHealth.cs

@@ -81,6 +81,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         /// </summary>
         public long PassGapMaxMs { get; set; }
 
+        /// <summary>
+        /// Platform-script runs whose emitted output IME's saved result (registry, after the batch
+        /// report) confirmed — the exit code of the same end block with it. Together with
+        /// <see cref="PlatformOutputCorrected"/> the field measure of the registry reconciliation (D-316).
+        /// </summary>
+        public long PlatformOutputVerified { get; set; }
+
+        /// <summary>Platform-script runs whose emitted output IME's saved result corrected (script_output_reconciliation).</summary>
+        public long PlatformOutputCorrected { get; set; }
+
         /// <summary>Match count per enabled pattern ID — every enabled pattern is present, zeros included.</summary>
         public IReadOnlyDictionary<string, int> PatternHits { get; set; }
 

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ImeTrackerStatePersistence.cs

@@ -151,6 +151,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         // that run from the start of the next one.
         public Dictionary<string, DateTime> PlatformScriptResultEmittedAt { get; set; }
         public List<ScriptExecutionState> PendingPlatformScripts { get; set; }
+        // Earlier runs that wait for their IME result while a later run of the same policy is in
+        // flight; a restart between reading AgentExecutor.log and the IME log must keep them. Null on
+        // older state files → none.
+        public List<ScriptExecutionState> ParkedPlatformScripts { get; set; }
         public List<string> ScriptTimeoutSuspectedPosted { get; set; }
 
         // Recurring health-script runs collapsed per policy. Saved in the same write as
@@ -185,6 +189,9 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
         // Poll-loop timing maxima (null-defaulting on older state files).
         public long PassMaxMs { get; set; }
         public long PassGapMaxMs { get; set; }
+        // Registry reconciliation of platform-script output (null-defaulting on older state files).
+        public long PlatformOutputVerified { get; set; }
+        public long PlatformOutputCorrected { get; set; }
     }
 
     public class PackageStateData

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/PlatformScriptRunRegister.cs

@@ -0,0 +1,196 @@
+using System;
+using System.Collections.Generic;
+
+namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime
+{
+    /// <summary>What the registry reconciliation may do with a saved IME result right now.</summary>
+    internal enum PlatformRunClaim
+    {
+        /// <summary>The run is handed out for reconciliation; it is never handed out again.</summary>
+        Claimed,
+        /// <summary>Not decidable yet: the tracker has not read past the save, or the run is not emitted yet.</summary>
+        Wait,
+        /// <summary>No run of this agent owns the save (none seen, or already reconciled).</summary>
+        None,
+    }
+
+    /// <summary>One platform-script run as the tracker emitted it; the register hands out copies.</summary>
+    internal sealed class PlatformScriptRun
+    {
+        public string PolicyId;
+        public string UserId;
+        public string RunId;
+        public DateTime StartSeenUtc;
+        public bool Emitted;
+        public bool Claimed;
+        public string Result;
+        public string ResultSource;
+        public int? ExitCode;
+        /// <summary>As emitted: null when no output line of the run was read, empty when it said so.</summary>
+        public string Stdout;
+        public string Stderr;
+
+        public PlatformScriptRun Clone() => (PlatformScriptRun)MemberwiseClone();
+    }
+
+    /// <summary>
+    /// The platform-script runs the tracker has seen, the latest per (IME user id, policy id), for the
+    /// registry reconciliation (D-316). IME saves a run's output under
+    /// <c>Policies\&lt;UserId&gt;\&lt;PolicyId&gt;</c> only after it reported the whole script batch, so the
+    /// observer reading it must know which run a changed key belongs to and what was emitted for it.
+    /// Written on the tracker's poll thread, claimed on the registry host's timer thread: every member
+    /// locks, and nothing calls out while holding the lock.
+    /// <para>
+    /// A save belongs to the latest run of its key: IME runs a policy at most once per check-in and
+    /// saves after reporting that check-in's batch, so the next run of the key comes with a later
+    /// check-in. (Overlapping check-ins can run a key twice at once; then IME itself shares the key's
+    /// result files and the judge's foreign verdict is the safety net.) A run that waited for its IME
+    /// result while a later run of its key already started is emitted without touching that later
+    /// run's entry. A save is paired only after the tracker completed a pass that started
+    /// <see cref="TrackerCatchUp"/> after the save was seen — every line written before the save, the
+    /// run's start among them, has been read by then, a stalled poll loop included.
+    /// </para>
+    /// </summary>
+    internal sealed class PlatformScriptRunRegister
+    {
+        /// <summary>
+        /// How far behind a seen save the tracker must have started a completed pass before the save
+        /// is paired; covers the ledger's verify cadence (1 s) for a start line hidden by an overwrite.
+        /// </summary>
+        internal static readonly TimeSpan TrackerCatchUp = TimeSpan.FromSeconds(2);
+
+        internal const int MaxRuns = 256;
+
+        private readonly object _sync = new object();
+        private readonly Dictionary<string, PlatformScriptRun> _latest =
+            new Dictionary<string, PlatformScriptRun>(StringComparer.OrdinalIgnoreCase);
+        private DateTime _lastCompletedPassStartUtc = DateTime.MinValue;
+        private long _verified;
+        private long _corrected;
+        private bool _countersChanged;
+
+        private static string KeyOf(string userId, string policyId) => (userId ?? string.Empty) + "|" + policyId;
+
+        /// <summary>A platform run began: its start line, or its result when no start line was seen.</summary>
+        public void NoteStarted(string userId, string policyId, DateTime seenUtc)
+        {
+            if (string.IsNullOrEmpty(policyId)) return;
+            lock (_sync)
+            {
+                _latest[KeyOf(userId, policyId)] = new PlatformScriptRun { PolicyId = policyId, UserId = userId, StartSeenUtc = seenUtc };
+                TrimLocked();
+            }
+        }
+
+        /// <summary>The tracker emitted the run with these end-block values.</summary>
+        public void NoteEmitted(ScriptExecutionState script, DateTime emittedUtc)
+        {
+            if (script == null || string.IsNullOrEmpty(script.PolicyId)) return;
+            lock (_sync)
+            {
+                var key = KeyOf(script.UserId, script.PolicyId);
+                if (!_latest.TryGetValue(key, out var run) || run.Emitted)
+                {
+                    run = new PlatformScriptRun { PolicyId = script.PolicyId, UserId = script.UserId, StartSeenUtc = emittedUtc };
+                    _latest[key] = run;
+                }
+                run.Emitted = true;
+                run.RunId = script.RunId;
+                run.Result = script.Result;
+                run.ResultSource = script.ResultSource;
+                run.ExitCode = script.ExitCode;
+                run.Stdout = script.Stdout;
+                run.Stderr = script.Stderr;
+                TrimLocked();
+            }
+        }
+
+        /// <summary>The tracker finished a poll pass that started at <paramref name="passStartedUtc"/>.</summary>
+        public void NotePassCompleted(DateTime passStartedUtc)
+        {
+            lock (_sync)
+            {
+                if (passStartedUtc > _lastCompletedPassStartUtc) _lastCompletedPassStartUtc = passStartedUtc;
+            }
+        }
+
+        /// <summary>
+        /// Hands out the run a save of (<paramref name="userId"/>, <paramref name="policyId"/>) seen at
+        /// <paramref name="savedSeenUtc"/> belongs to — once. A run whose user id the tracker could not
+        /// read is keyed without one.
+        /// </summary>
+        public PlatformRunClaim TryClaim(string userId, string policyId, DateTime savedSeenUtc, out PlatformScriptRun run)
+        {
+            run = null;
+            lock (_sync)
+            {
+                if (_lastCompletedPassStartUtc < savedSeenUtc + TrackerCatchUp) return PlatformRunClaim.Wait;
+
+                if (!_latest.TryGetValue(KeyOf(userId, policyId), out var latest)
+                    && !_latest.TryGetValue(KeyOf(null, policyId), out latest))
+                    return PlatformRunClaim.None;
+                if (latest.Claimed) return PlatformRunClaim.None;
+                if (!latest.Emitted) return PlatformRunClaim.Wait;
+
+                latest.Claimed = true;
+                run = latest.Clone();
+                return PlatformRunClaim.Claimed;
+            }
+        }
+
+        public void CountVerified()
+        {
+            lock (_sync) { _verified++; _countersChanged = true; }
+        }
+
+        public void CountCorrected()
+        {
+            lock (_sync) { _corrected++; _countersChanged = true; }
+        }
+
+        /// <summary>Runs whose emitted output IME's saved result confirmed (restart-safe, session-cumulative).</summary>
+        public long Verified { get { lock (_sync) return _verified; } }
+
+        /// <summary>Runs whose emitted output IME's saved result corrected (restart-safe, session-cumulative).</summary>
+        public long Corrected { get { lock (_sync) return _corrected; } }
+
+        public void RestoreCounters(long verified, long corrected)
+        {
+            lock (_sync)
+            {
+                _verified = verified;
+                _corrected = corrected;
+            }
+        }
+
+        /// <summary>True once after a counter moved — the tracker then persists its state.</summary>
+        public bool ConsumeCountersChanged()
+        {
+            lock (_sync)
+            {
+                var changed = _countersChanged;
+                _countersChanged = false;
+                return changed;
+            }
+        }
+
+        private void TrimLocked()
+        {
+            while (_latest.Count > MaxRuns)
+            {
+                string oldestKey = null;
+                var oldest = DateTime.MaxValue;
+                foreach (var kv in _latest)
+                {
+                    if (kv.Value.StartSeenUtc < oldest)
+                    {
+                        oldest = kv.Value.StartSeenUtc;
+                        oldestKey = kv.Key;
+                    }
+                }
+                if (oldestKey == null) return;
+                _latest.Remove(oldestKey);
+            }
+        }
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/Ime/ScriptExecutionState.cs

@@ -15,6 +15,28 @@ public class ScriptExecutionState
     /// <summary>"platform" or "remediation".</summary>
     public string ScriptType { get; set; }
 
+    /// <summary>
+    /// IME user id a platform script ran for (the all-zero GUID in device context), read from its
+    /// script path or its result line. Keys IME's saved result
+    /// (<c>Policies\&lt;UserId&gt;\&lt;PolicyId&gt;</c>) that the registry reconciliation compares against.
+    /// </summary>
+    public string UserId { get; set; }
+
+    /// <summary>
+    /// Identity of one platform-script run, given when its slot opens and surfaced as <c>runId</c> on
+    /// the event: the invocation markers bind the run's executor lines to it, and a later
+    /// <c>script_output_reconciliation</c> names it when it corrects that run.
+    /// </summary>
+    public string RunId { get; set; }
+
+    /// <summary>
+    /// Source timestamp of the run's AgentExecutor start line (<c>Adding argument powershell with
+    /// value …</c>). Every executor process writes that line once, so a later one for the same
+    /// policy starts the next run, never this one. Null until the line is read, and on state files
+    /// from before the field.
+    /// </summary>
+    public System.DateTime? ExecutorStartedAtUtc { get; set; }
+
     /// <summary>
     /// UTC timestamp of the script's first observed start line, taken from the source CMTrace log
     /// timestamp (so it dates correctly even when the agent replays historic IME log content that

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/EspAndHelloTracker.cs

@@ -366,6 +366,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         public void BackfillRecentHelloWizardStart(int lookbackMinutes)
             => _shellCoreTracker?.BackfillRecentHelloWizardStart(lookbackMinutes);
 
+        /// <summary>
+        /// First run only: the update page's records from before the agent started, as telemetry
+        /// and nothing else — see <see cref="ShellCoreTracker.BackfillUpdatePageTelemetry"/>.
+        /// </summary>
+        public void BackfillUpdatePageTelemetry(int lookbackMinutes)
+            => _shellCoreTracker?.BackfillUpdatePageTelemetry(lookbackMinutes);
+
         /// <summary>
         /// sits-d Cloud-PC fix (2026-08-19) — re-check the user-apps-settled AccountSetup
         /// synthesis after the ESP exit has already been observed. Wired to the IME tracker's

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/ImeRegistryScriptResultObserver.cs

@@ -0,0 +1,401 @@
+#nullable enable
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text.Json;
+using AutopilotMonitor.Agent.V2.Core.Logging;
+using AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.Ime;
+using AutopilotMonitor.Agent.V2.Core.Orchestration;
+using AutopilotMonitor.DecisionCore.Engine;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Win32;
+using SharedEventTypes = AutopilotMonitor.Shared.Constants.EventTypes;
+
+namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
+{
+    /// <summary>
+    /// Registry second pillar for platform scripts (D-316). After IME reported a script batch to
+    /// Intune it saves every run of the batch under
+    /// <c>HKLM\SOFTWARE\Microsoft\IntuneManagementExtension\Policies\&lt;UserId&gt;\&lt;PolicyId&gt;</c>:
+    /// <c>Result</c>, <c>ErrorCode</c> and <c>ResultDetails</c>, whose <c>ExecutionMsg</c> is what IME read
+    /// from the result file of exactly that policy — the stdout when the run succeeded (IME's Success
+    /// means an empty stderr file, whatever the exit code), the stderr when it failed with ErrorCode 99.
+    /// The log tracker assigns a run's exit code and output by file position in AgentExecutor.log, where
+    /// no policy id anchors them; this observer checks what was emitted against the keyed value and
+    /// emits <c>script_output_reconciliation</c> when they disagree.
+    /// <para>
+    /// Snapshot-and-diff like <see cref="ImeRegistryAppStateObserver"/>, ticked by the same host: the
+    /// first tick is the silent baseline, a later save is paired with its run through
+    /// <see cref="PlatformScriptRunRegister"/>. No exit code lives in the registry: a run whose output
+    /// matches proves the exit code of the same end block; a contradicted run loses its exit code.
+    /// </para>
+    /// </summary>
+    internal sealed class ImeRegistryScriptResultObserver
+    {
+        public const string SourceLabel = "RegistryScriptResult";
+
+        internal const string PoliciesKeyPath = ImeRegistryAppStateObserver.ImeRootKeyPath + @"\Policies";
+
+        /// <summary>A save whose run never became claimable is dropped after this long (send failure of a later batch, agent restart).</summary>
+        internal static readonly TimeSpan PendingExpiry = TimeSpan.FromMinutes(10);
+
+        /// <summary>Safety cap on correction events per agent run; corrections beyond it are counted only.</summary>
+        internal const int MaxCorrectionsPerSession = 100;
+
+        private readonly PlatformScriptRunRegister _runs;
+        private readonly Func<IReadOnlyDictionary<string, SavedScriptResult>> _snapshotSource;
+        private readonly InformationalEventPost _post;
+        private readonly AgentLogger? _logger;
+        private readonly IClock _clock;
+        private readonly object _sync = new object();
+
+        private IReadOnlyDictionary<string, SavedScriptResult>? _last;
+        private readonly Dictionary<string, (SavedScriptResult Saved, DateTime SeenUtc)> _pending =
+            new Dictionary<string, (SavedScriptResult, DateTime)>(StringComparer.OrdinalIgnoreCase);
+        private int _correctionsEmitted;
+
+        /// <param name="snapshotSource">Replaces the live registry walk in tests; per instance, so parallel test classes never share it.</param>
+        public ImeRegistryScriptResultObserver(
+            PlatformScriptRunRegister runs,
+            InformationalEventPost post,
+            AgentLogger? logger,
+            IClock clock,
+            Func<IReadOnlyDictionary<string, SavedScriptResult>>? snapshotSource = null)
+        {
+            _runs = runs ?? throw new ArgumentNullException(nameof(runs));
+            _post = post ?? throw new ArgumentNullException(nameof(post));
+            _clock = clock ?? throw new ArgumentNullException(nameof(clock));
+            _logger = logger;
+            _snapshotSource = snapshotSource ?? ReadSnapshot;
+        }
+
+        /// <summary>One observation pass: snapshot → new saves → pair → judge → correct. Fail-soft: never throws.</summary>
+        public void Tick(string reason)
+        {
+            try
+            {
+                lock (_sync)
+                {
+                    var snapshot = _snapshotSource();
+                    var nowUtc = _clock.UtcNow;
+
+                    if (_last == null)
+                    {
+                        // Saves that predate this agent run belong to runs it never emitted.
+                        _last = snapshot;
+                        _logger?.Info($"RegistryScriptResult: baseline captured ({snapshot.Count} saved platform-script results, trigger={reason})");
+                        return;
+                    }
+
+                    foreach (var kv in snapshot)
+                    {
+                        if (_last.TryGetValue(kv.Key, out var previous) && previous.SameSaveAs(kv.Value)) continue;
+                        _pending[kv.Key] = (kv.Value, nowUtc); // a newer save of the key replaces a waiting one
+                    }
+                    _last = snapshot;
+
+                    ProcessPending(nowUtc);
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger?.Debug($"RegistryScriptResult: tick failed (fail-soft): {ex.Message}");
+            }
+        }
+
+        private void ProcessPending(DateTime nowUtc)
+        {
+            foreach (var key in _pending.Keys.ToList())
+            {
+                var (saved, seenUtc) = _pending[key];
+                var claim = _runs.TryClaim(saved.UserId, saved.PolicyId, seenUtc, out var run);
+                if (claim == PlatformRunClaim.Wait)
+                {
+                    if (nowUtc - seenUtc >= PendingExpiry) _pending.Remove(key);
+                    continue;
+                }
+
+                _pending.Remove(key);
+                if (claim == PlatformRunClaim.Claimed && run != null) Reconcile(run, saved, nowUtc);
+            }
+        }
+
+        private void Reconcile(PlatformScriptRun run, SavedScriptResult saved, DateTime nowUtc)
+        {
+            var judgement = PlatformOutputJudge.Judge(run, saved);
+            switch (judgement.Verdict)
+            {
+                case PlatformOutputVerdict.Verified:
+                    _runs.CountVerified();
+                    _logger?.Debug($"RegistryScriptResult: platform script {run.PolicyId} output confirmed by IME's saved result");
+                    return;
+                case PlatformOutputVerdict.NotComparable:
+                    _logger?.Debug($"RegistryScriptResult: platform script {run.PolicyId} not comparable ({judgement.Reason})");
+                    return;
+            }
+
+            _runs.CountCorrected();
+            if (_correctionsEmitted >= MaxCorrectionsPerSession)
+            {
+                _logger?.Warning($"RegistryScriptResult: correction for {run.PolicyId} not emitted — cap of {MaxCorrectionsPerSession} per agent run reached");
+                return;
+            }
+            _correctionsEmitted++;
+
+            var foreign = judgement.Verdict == PlatformOutputVerdict.Foreign;
+            var culture = CultureInfo.InvariantCulture;
+            var data = new Dictionary<string, string>(StringComparer.Ordinal)
+            {
+                ["policyId"] = run.PolicyId,
+                ["scriptType"] = "platform",
+                ["outcome"] = foreign ? "foreign" : "repaired",
+                ["reason"] = judgement.Reason,
+            };
+            if (!string.IsNullOrEmpty(run.RunId)) data["runId"] = run.RunId!;
+            if (!string.IsNullOrEmpty(saved.Result)) data["result"] = saved.Result!;
+            if (saved.ErrorCode.HasValue) data["registryErrorCode"] = saved.ErrorCode.Value.ToString(culture);
+            // A present key replaces the emitted value, an empty one clears it; an absent key keeps it.
+            if (judgement.Stdout != null) data["stdout"] = judgement.Stdout;
+            if (judgement.Stderr != null) data["stderr"] = judgement.Stderr;
+            if (foreign && run.ExitCode.HasValue) data["previousExitCode"] = run.ExitCode.Value.ToString(culture);
+
+            var shortId = run.PolicyId.Length > 8 ? run.PolicyId.Substring(0, 8) : run.PolicyId;
+            var message = foreign
+                ? $"Platform script {shortId}: output corrected from IME's saved result; the log had attributed another script's output, exit code unverified"
+                : $"Platform script {shortId}: output completed from IME's saved result";
+
+            _post.Emit(
+                eventType: SharedEventTypes.ScriptOutputReconciliation,
+                source: SourceLabel,
+                message: message,
+                severity: foreign ? EventSeverity.Warning : EventSeverity.Info,
+                immediateUpload: foreign,
+                data: data,
+                occurredAtUtc: nowUtc);
+
+            if (foreign)
+                _logger?.Warning($"RegistryScriptResult: platform script {run.PolicyId} run {run.RunId} carried another script's end block ({judgement.Reason}) — corrected from IME's saved result");
+            else
+                _logger?.Info($"RegistryScriptResult: platform script {run.PolicyId} run {run.RunId} output completed from IME's saved result ({judgement.Reason})");
+        }
+
+        // ── snapshot ────────────────────────────────────────────────────────────
+
+        internal static string KeyOf(string userId, string policyId) => userId + "|" + policyId;
+
+        internal static IReadOnlyDictionary<string, SavedScriptResult> ReadSnapshot()
+        {
+            var snapshot = new Dictionary<string, SavedScriptResult>(StringComparer.OrdinalIgnoreCase);
+            using var baseKey = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64);
+            using var policies = baseKey.OpenSubKey(PoliciesKeyPath);
+            if (policies == null) return snapshot;
+
+            foreach (var userId in policies.GetSubKeyNames())
+            {
+                if (!Guid.TryParse(userId, out _)) continue;
+                using var userKey = policies.OpenSubKey(userId);
+                if (userKey == null) continue;
+
+                foreach (var policyId in userKey.GetSubKeyNames())
+                {
+                    if (!Guid.TryParse(policyId, out _)) continue;
+                    using var policyKey = userKey.OpenSubKey(policyId);
+                    if (policyKey == null) continue;
+
+                    snapshot[KeyOf(userId, policyId)] = new SavedScriptResult
+                    {
+                        UserId = userId,
+                        PolicyId = policyId,
+                        Result = policyKey.GetValue("Result") as string,
+                        ErrorCode = TryReadInt(policyKey.GetValue("ErrorCode")),
+                        ResultDetails = policyKey.GetValue("ResultDetails") as string,
+                        LastUpdatedTimeUtc = policyKey.GetValue("LastUpdatedTimeUtc") as string,
+                    };
+                }
+            }
+            return snapshot;
+        }
+
+        private static int? TryReadInt(object? value)
+        {
+            switch (value)
+            {
+                case int i: return i;
+                case long l when l >= int.MinValue && l <= int.MaxValue: return (int)l;
+                case string s when int.TryParse(s, NumberStyles.Integer, CultureInfo.InvariantCulture, out var parsed): return parsed;
+                default: return null;
+            }
+        }
+    }
+
+    /// <summary>One platform-script result as IME saved it under <c>Policies\&lt;UserId&gt;\&lt;PolicyId&gt;</c>.</summary>
+    internal sealed class SavedScriptResult
+    {
+        public string UserId { get; set; } = string.Empty;
+        public string PolicyId { get; set; } = string.Empty;
+        public string? Result { get; set; }
+        public int? ErrorCode { get; set; }
+        public string? ResultDetails { get; set; }
+        public string? LastUpdatedTimeUtc { get; set; }
+
+        /// <summary>The same save: IME stamps every save with a new <c>LastUpdatedTimeUtc</c>.</summary>
+        public bool SameSaveAs(SavedScriptResult other)
+            => string.Equals(LastUpdatedTimeUtc, other.LastUpdatedTimeUtc, StringComparison.Ordinal)
+            && string.Equals(Result, other.Result, StringComparison.Ordinal)
+            && ErrorCode == other.ErrorCode
+            && string.Equals(ResultDetails, other.ResultDetails, StringComparison.Ordinal);
+
+        /// <summary>
+        /// <c>ExecutionMsg</c> of the CryptoResult JSON in <c>ResultDetails</c> (IME 1.73 and later), or null
+        /// when the value is not that JSON ("Hash mismatch", a launch failure).
+        /// </summary>
+        public string? ExecutionMessage()
+        {
+            if (string.IsNullOrWhiteSpace(ResultDetails)) return null;
+            try
+            {
+                using var doc = JsonDocument.Parse(ResultDetails!);
+                if (doc.RootElement.ValueKind != JsonValueKind.Object) return null;
+                return doc.RootElement.TryGetProperty("ExecutionMsg", out var msg) && msg.ValueKind == JsonValueKind.String
+                    ? msg.GetString()
+                    : null;
+            }
+            catch (JsonException)
+            {
+                return null;
+            }
+        }
+    }
+
+    internal enum PlatformOutputVerdict
+    {
+        /// <summary>IME's saved result cannot confirm or contradict the run (no output saved, other failure kind).</summary>
+        NotComparable,
+        /// <summary>The emitted output is what IME saved: the end block, its exit code included, is the run's own.</summary>
+        Verified,
+        /// <summary>The log delivered the run's output incomplete; IME's saved text completes it, the exit code stands.</summary>
+        Repaired,
+        /// <summary>The emitted output contradicts IME's saved result: the end block was another executor's.</summary>
+        Foreign,
+    }
+
+    internal sealed class PlatformOutputJudgement
+    {
+        public PlatformOutputVerdict Verdict { get; set; }
+        public string Reason { get; set; } = string.Empty;
+        /// <summary>Value to publish (Repaired/Foreign): null keeps the emitted stdout, empty clears it.</summary>
+        public string? Stdout { get; set; }
+        /// <summary>Value to publish (Repaired/Foreign): null keeps the emitted stderr, empty clears it.</summary>
+        public string? Stderr { get; set; }
+    }
+
+    /// <summary>
+    /// Compares a platform-script run as the tracker emitted it with IME's saved result. Comparable are
+    /// a Success (ExecutionMsg = stdout; IME's Success means the stderr file was empty) and a Failed with
+    /// ErrorCode 99 (ExecutionMsg = stderr). Both texts are compared after CR/LF normalisation and Trim;
+    /// the tracker's own 8192-character cut is a prefix of the saved text.
+    /// </summary>
+    internal static class PlatformOutputJudge
+    {
+        internal const int ImeStderrErrorCode = 99;
+        private const string OutputErrorSeparator = ", error =";
+
+        public static PlatformOutputJudgement Judge(PlatformScriptRun run, SavedScriptResult saved)
+        {
+            var executionMessage = saved.ExecutionMessage();
+            if (executionMessage == null) return NotComparable("no_execution_message");
+
+            // The run's IME result line and the save come from the same IME run.
+            if (string.Equals(run.ResultSource, "ime_policy_result", StringComparison.Ordinal)
+                && !string.Equals(run.Result, saved.Result, StringComparison.OrdinalIgnoreCase))
+                return NotComparable("result_differs");
+
+            if (string.Equals(saved.Result, "Success", StringComparison.OrdinalIgnoreCase))
+                return JudgeSuccess(run, Normalize(executionMessage)!);
+            if (string.Equals(saved.Result, "Failed", StringComparison.OrdinalIgnoreCase) && saved.ErrorCode == ImeStderrErrorCode)
+                return JudgeStderrFailure(run, Normalize(executionMessage)!);
+            return NotComparable("no_saved_output");
+        }
+
+        private static PlatformOutputJudgement JudgeSuccess(PlatformScriptRun run, string savedStdout)
+        {
+            var stdout = NormalizeEmitted(run.Stdout, out var stdoutCut);
+            var stderr = Normalize(run.Stderr);
+            var stderrClean = string.IsNullOrEmpty(stderr);
+
+            if (!string.IsNullOrEmpty(stdout) && Agrees(stdout!, stdoutCut, savedStdout))
+                return stderrClean ? Verified() : Correct(PlatformOutputVerdict.Repaired, "stderr_cleared", savedStdout, string.Empty);
+
+            if (stdout != null && stdout.Length == 0 && savedStdout.Length == 0)
+                return stderrClean ? Verified() : Correct(PlatformOutputVerdict.Foreign, "stderr_on_success", string.Empty, string.Empty);
+
+            if (stdout == null)
+            {
+                if (!stderrClean) return Correct(PlatformOutputVerdict.Foreign, "stderr_on_success", savedStdout, string.Empty);
+                return savedStdout.Length > 0
+                    ? Correct(PlatformOutputVerdict.Repaired, "stdout_missing", savedStdout, string.Empty)
+                    : NotComparable("nothing_read");
+            }
+
+            // "write output done. output = X, error = Y" splits at the first ", error =" — a stdout that
+            // contains the separator ends up partly in stderr. The saved text shows the cut right there.
+            if (stdout.Length > 0 && !stdoutCut && !stderrClean
+                && savedStdout.StartsWith(stdout, StringComparison.Ordinal)
+                && savedStdout.Substring(stdout.Length).TrimStart().StartsWith(OutputErrorSeparator, StringComparison.Ordinal))
+                return Correct(PlatformOutputVerdict.Repaired, "stdout_split", savedStdout, string.Empty);
+
+            return Correct(PlatformOutputVerdict.Foreign, "stdout_differs", savedStdout, string.Empty);
+        }
+
+        private static PlatformOutputJudgement JudgeStderrFailure(PlatformScriptRun run, string savedStderr)
+        {
+            var stderr = NormalizeEmitted(run.Stderr, out var stderrCut);
+            if (!string.IsNullOrEmpty(stderr) && Agrees(stderr!, stderrCut, savedStderr)) return Verified();
+
+            // Nothing of the end block read: complete the stderr, the run's stdout stays as emitted.
+            if (run.Stderr == null && run.Stdout == null)
+                return Correct(PlatformOutputVerdict.Repaired, "stderr_missing", null, savedStderr);
+
+            // The end block read said something else — an empty stderr included: IME read stderr from this
+            // run's error file. The block's stdout is the other executor's as well.
+            return Correct(PlatformOutputVerdict.Foreign, "stderr_differs", string.Empty, savedStderr);
+        }
+
+        private static bool Agrees(string emitted, bool emittedCut, string saved)
+            => string.Equals(emitted, saved, StringComparison.Ordinal)
+            || (emittedCut && saved.StartsWith(emitted, StringComparison.Ordinal));
+
+        /// <summary>CR LF and lone CR to LF, then Trim — what the tracker's line reader and handlers make of a text.</summary>
+        internal static string? Normalize(string? text)
+            => text?.Replace("\r\n", "\n").Replace('\r', '\n').Trim();
+
+        private static string? NormalizeEmitted(string? text, out bool cut)
+        {
+            cut = false;
+            if (text == null) return null;
+            if (text.EndsWith(ImeLogTracker.OutputTruncationMarker, StringComparison.Ordinal))
+            {
+                cut = true;
+                text = text.Substring(0, text.Length - ImeLogTracker.OutputTruncationMarker.Length);
+            }
+            return Normalize(text);
+        }
+
+        private static PlatformOutputJudgement Verified()
+            => new PlatformOutputJudgement { Verdict = PlatformOutputVerdict.Verified, Reason = "match" };
+
+        private static PlatformOutputJudgement NotComparable(string reason)
+            => new PlatformOutputJudgement { Verdict = PlatformOutputVerdict.NotComparable, Reason = reason };
+
+        private static PlatformOutputJudgement Correct(PlatformOutputVerdict verdict, string reason, string? stdout, string? stderr)
+            => new PlatformOutputJudgement
+            {
+                Verdict = verdict,
+                Reason = reason,
+                // The tracker's own output cap: a corrected value is never longer than an emitted one.
+                Stdout = stdout == null ? null : ImeLogTracker.TruncateOutput(stdout),
+                Stderr = stderr == null ? null : ImeLogTracker.TruncateOutput(stderr),
+            };
+    }
+}

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/OobeUpdateTelemetry.cs

@@ -18,6 +18,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         public const string PageStopped = "page_stopped";
         public const string EventName = "event_name";
 
+        /// <summary>
+        /// Not a record: the <c>cxhEvent</c> of the marker <see cref="OobeUpdateTelemetry"/> sends
+        /// once per budget when the event names of a run start staying in agent.log.
+        /// </summary>
+        public const string NamesCapped = "names_capped";
+
         public OobeUpdatePageRecord(string cxhEvent, int windowsEventId, string page = null, string result = null, string name = null, string value = null)
         {
             CxhEvent = cxhEvent;
@@ -54,6 +60,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
     internal sealed class OobeUpdateTelemetry
     {
         internal const int MaxPageEventsPerRun = 150;
+
+        /// <summary>
+        /// Event names the backfills (first run, restart) report per run — their own budget, so
+        /// the records from before the agent started cannot spend the live page's.
+        /// </summary>
+        internal const int MaxBackfillPageEventsPerRun = 150;
+
         internal const int MaxPageEventsPerKey = 3;
         internal const int MaxStateEventsPerRun = 6;
         internal const int MaxStateLineLength = 1000;
@@ -67,7 +80,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
             public const string AgentStop = "agent_stop";
         }
 
-        private const string Source = "ShellCoreTracker";
+        private const string Source = Constants.EventSources.ShellCoreTracker;
 
         private readonly string _sessionId;
         private readonly string _tenantId;
@@ -77,8 +90,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
 
         private readonly object _lock = new object();
         private readonly Dictionary<string, int> _pageEventsPerKey = new Dictionary<string, int>(StringComparer.Ordinal);
-        private int _pageEvents;
-        private bool _pageCapLogged;
+        private int _livePageEvents;
+        private int _backfillPageEvents;
+        private bool _liveCapReported;
+        private bool _backfillCapReported;
         private int _stateEvents;
         private string _lastStateContent;
 
@@ -99,9 +114,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         /// <summary>
         /// One <c>oobe_update_page</c> per update-page record, at most
         /// <see cref="MaxPageEventsPerKey"/> per page/name — a page that logs the same name in a
-        /// loop cannot flood the session. Event names also share <see cref="MaxPageEventsPerRun"/>
-        /// per run; a page start or stop is outside that budget, because the time attribution
-        /// reads the update's span from them. True when the record was reported.
+        /// loop cannot flood the session. Event names also share a budget per run: live ones
+        /// <see cref="MaxPageEventsPerRun"/>, backfilled ones <see cref="MaxBackfillPageEventsPerRun"/>;
+        /// the first name over a budget sends the <see cref="OobeUpdatePageRecord.NamesCapped"/>
+        /// marker. A page start or stop is outside the budgets, because the time attribution reads
+        /// the update's span from them. True when the record was reported.
         /// </summary>
         public bool ReportPage(OobeUpdatePageRecord record, DateTime occurredAtUtc, bool isBackfill)
         {
@@ -109,23 +126,37 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
 
             var isEventName = record.CxhEvent == OobeUpdatePageRecord.EventName;
             var key = $"{record.CxhEvent}:{record.Page ?? record.Name}";
-            int occurrence;
+            var budget = isBackfill ? MaxBackfillPageEventsPerRun : MaxPageEventsPerRun;
+            var occurrence = 0;
+            bool overBudget;
+            var firstOverBudget = false;
             lock (_lock)
             {
-                if (isEventName && _pageEvents >= MaxPageEventsPerRun)
+                overBudget = isEventName && (isBackfill ? _backfillPageEvents : _livePageEvents) >= budget;
+                if (overBudget)
                 {
-                    if (!_pageCapLogged)
-                    {
-                        _pageCapLogged = true;
-                        _logger.Info($"OOBE update page telemetry: {MaxPageEventsPerRun} event names reached, the rest of this run stays in agent.log");
-                    }
-                    return false;
+                    firstOverBudget = isBackfill ? !_backfillCapReported : !_liveCapReported;
+                    if (isBackfill) _backfillCapReported = true;
+                    else _liveCapReported = true;
                 }
-                _pageEventsPerKey.TryGetValue(key, out occurrence);
-                if (occurrence >= MaxPageEventsPerKey) return false;
-                occurrence++;
-                _pageEventsPerKey[key] = occurrence;
-                if (isEventName) _pageEvents++;
+                else
+                {
+                    _pageEventsPerKey.TryGetValue(key, out occurrence);
+                    if (occurrence >= MaxPageEventsPerKey) return false;
+                    occurrence++;
+                    _pageEventsPerKey[key] = occurrence;
+                    if (isEventName)
+                    {
+                        if (isBackfill) _backfillPageEvents++;
+                        else _livePageEvents++;
+                    }
+                }
+            }
+
+            if (overBudget)
+            {
+                if (firstOverBudget) ReportNamesCapped(budget, occurredAtUtc, isBackfill);
+                return false;
             }
 
             var data = new Dictionary<string, object>
@@ -141,6 +172,32 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
             if (record.Name != null) data["name"] = record.Name;
             if (record.Value != null) data["value"] = record.Value;
 
+            return EmitPage(occurredAtUtc, DescribePage(record), data);
+        }
+
+        /// <summary>
+        /// The marker that a budget is spent: from here on this run's live or backfilled event
+        /// names stay in agent.log, so a name missing from the session proves nothing — the
+        /// analyze rules that read an absent name check for this marker first.
+        /// </summary>
+        private void ReportNamesCapped(int budget, DateTime occurredAtUtc, bool isBackfill)
+        {
+            var kind = isBackfill ? "backfilled " : string.Empty;
+            _logger.Info($"OOBE update page telemetry: {budget} {kind}event names reached, the rest of this run stays in agent.log");
+
+            EmitPage(occurredAtUtc,
+                $"OOBE update page: {budget} {kind}event names reached, later ones of this agent run are not sent",
+                new Dictionary<string, object>
+                {
+                    { "cxhEvent", OobeUpdatePageRecord.NamesCapped },
+                    { "eventTime", occurredAtUtc.ToString("o") },
+                    { "backfill", isBackfill },
+                    { "limit", budget },
+                });
+        }
+
+        private bool EmitPage(DateTime occurredAtUtc, string message, Dictionary<string, object> data)
+        {
             try
             {
                 _post.Emit(new EnrollmentEvent
@@ -152,7 +209,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                     Severity = EventSeverity.Debug,
                     Source = Source,
                     Phase = EnrollmentPhase.Unknown,
-                    Message = DescribePage(record),
+                    Message = message,
                     Data = data,
                     ImmediateUpload = false,
                 });

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/ServicingTracker.cs

@@ -280,7 +280,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                 Timestamp = timeCreatedUtc ?? DateTime.UtcNow,
                 EventType = Constants.EventTypes.WindowsUpdateServicing,
                 Severity = severity,
-                Source = "ServicingWatcher",
+                Source = Constants.EventSources.ServicingWatcher,
                 Phase = EnrollmentPhase.Unknown,
                 Message = message,
                 Data = data,

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/ShellCoreTracker.cs

@@ -51,6 +51,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         /// </summary>
         internal const int BackfillLookbackMaxMinutes = 360;
 
+        /// <summary>
+        /// Lookback of the first run's update page backfill (<see cref="BackfillUpdatePageTelemetry"/>)
+        /// — the hour the servicing watcher reads back, so the page's records and the update's
+        /// servicing steps cover the same time.
+        /// </summary>
+        internal const int UpdatePageBackfillLookbackMinutes = 60;
+
         private static readonly HashSet<int> TrackedShellCoreEventIds = new HashSet<int>
         {
             EventId_ShellCore_WebAppStarted,
@@ -100,7 +107,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         private bool _espExitDetected;
         private bool _whiteGloveDetected;
         private bool _helloWizardStartDetected;
-        private string _lastCxhPage; // 62405 names no page, it ends the last one started
+        // 62405 names no page, it ends the last one started. The live watcher's page; a backfill
+        // moves it only with a newer record (see ObserveCxhRecord).
+        private string _lastCxhPage;
+        private long _lastCxhPageRecordId = -1;
         private readonly object _stateLock = new object();
 
         /// <summary>
@@ -194,7 +204,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                 // WhiteGlove success — indistinguishable on the backend from a real no-signal
                 // enrollment. Surface it as one-shot telemetry.
                 CollectorDegradationReporter.Report(_post, _sessionId, _tenantId,
-                    collectorName: "ShellCoreTracker", reason: "watcher_arm_failed", ex: ex);
+                    collectorName: Constants.EventSources.ShellCoreTracker, reason: "watcher_arm_failed", ex: ex);
             }
         }
 
@@ -258,7 +268,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
             IReadOnlyList<string> properties = null)
         {
             var fields = ReadCxhFields(eventId, description, properties);
-            ObserveCxhRecord(eventId, fields, timestamp, isBackfill, recordId);
+            ObserveCxhRecord(eventId, fields, timestamp, isBackfill, recordId, backfillPage: null);
             if (eventId == EventId_ShellCore_WebAppStopped || eventId == EventId_ShellCore_WebAppEventName) return;
 
             string eventType;
@@ -459,31 +469,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         {
             try
             {
-                var lookbackMs = ClampLookbackMinutes(lookbackMinutes) * 60 * 1000;
-                var query = new EventLogQuery(
-                    ShellCoreEventLogChannel,
-                    PathType.LogName,
-                    $"*[System[{WatchedEventIdsXPath} and TimeCreated[timediff(@SystemTime) <= {lookbackMs}]]]");
-
-                var records = new List<ShellCoreRecord>();
-                using (var reader = new EventLogReader(query))
-                {
-                    for (EventRecord record = reader.ReadEvent(); record != null; record = reader.ReadEvent())
-                    {
-                        using (record)
-                        {
-                            var description = record.FormatDescription() ?? "";
-                            // Preserve the historical event time across backfill so subscribers
-                            // (EspAndHelloTrackerAdapter) can stamp signals with the source time
-                            // rather than collapsing to wall-clock-now.
-                            var timestamp = (record.TimeCreated ?? DateTime.UtcNow).ToUniversalTime();
-                            records.Add(new ShellCoreRecord(record.Id, description, timestamp,
-                                record.RecordId ?? -1, ReadProperties(record)));
-                        }
-                    }
-                }
-
-                ReplayBackfillRecords(records);
+                ReplayBackfillRecords(ReadRecentRecords(lookbackMinutes));
             }
             catch (Exception ex)
             {
@@ -491,6 +477,76 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
             }
         }
 
+        /// <summary>
+        /// The FIRST run's counterpart of the restart replay, for telemetry only: the update
+        /// page's records of the last <paramref name="lookbackMinutes"/> minutes (clamped like
+        /// the replay) become <c>oobe_update_page</c> rows. The agent is installed during the ESP
+        /// and can start after the update page began; without this its time attribution has no
+        /// page start to begin the update with (field: a first run 7 min after the update's
+        /// restart saw neither the page start nor the update's first half).
+        /// <para>
+        /// Nothing else is looked at: no Hello-wizard replay, no ESP exit or failure count, no
+        /// <c>agent_trace</c>. The first run keeps its decision behaviour exactly — see
+        /// <see cref="ReplayBackfillRecords"/> for why no replayed record may reach the engine and
+        /// <c>DefaultComponentFactory.ResolveEspExitBackfillLookbackMinutes</c> for why the first
+        /// run has no replay. No boot bound: an agent that first starts after the update's restart
+        /// is exactly the case to cover; the RecordId watermark keeps it from re-sending.
+        /// </para>
+        /// </summary>
+        public void BackfillUpdatePageTelemetry(int lookbackMinutes)
+        {
+            try
+            {
+                ReplayUpdatePageTelemetry(ReadRecentRecords(lookbackMinutes));
+            }
+            catch (Exception ex)
+            {
+                _logger.Warning($"Shell-Core update page backfill failed: {ex.Message}");
+            }
+        }
+
+        /// <summary>The update page telemetry of a chronological batch of Shell-Core records — nothing else.</summary>
+        internal void ReplayUpdatePageTelemetry(IReadOnlyList<ShellCoreRecord> records)
+        {
+            if (records == null || records.Count == 0) return;
+
+            var page = new BackfillPageCursor();
+            foreach (var record in records)
+            {
+                var fields = ReadCxhFields(record.Id, record.Description ?? string.Empty, record.Properties);
+                ObserveCxhRecord(record.Id, fields, record.OccurredAtUtc, isBackfill: true, recordId: record.RecordId, backfillPage: page);
+            }
+        }
+
+        /// <summary>The watched Shell-Core records of the last minutes, oldest first, with their original event time.</summary>
+        private List<ShellCoreRecord> ReadRecentRecords(int lookbackMinutes)
+        {
+            var lookbackMs = ClampLookbackMinutes(lookbackMinutes) * 60 * 1000;
+            var query = new EventLogQuery(
+                ShellCoreEventLogChannel,
+                PathType.LogName,
+                $"*[System[{WatchedEventIdsXPath} and TimeCreated[timediff(@SystemTime) <= {lookbackMs}]]]");
+
+            var records = new List<ShellCoreRecord>();
+            using (var reader = new EventLogReader(query))
+            {
+                for (EventRecord record = reader.ReadEvent(); record != null; record = reader.ReadEvent())
+                {
+                    using (record)
+                    {
+                        var description = record.FormatDescription() ?? "";
+                        // Preserve the historical event time across backfill so subscribers
+                        // (EspAndHelloTrackerAdapter) can stamp signals with the source time
+                        // rather than collapsing to wall-clock-now.
+                        var timestamp = (record.TimeCreated ?? DateTime.UtcNow).ToUniversalTime();
+                        records.Add(new ShellCoreRecord(record.Id, description, timestamp,
+                            record.RecordId ?? -1, ReadProperties(record)));
+                    }
+                }
+            }
+            return records;
+        }
+
         /// <summary>
         /// Replays a chronological batch of Shell-Core records. <b>Only the Hello-wizard start
         /// (62404) is replayed.</b> ESP exits and ESP failures (62407) are counted and reported,
@@ -546,12 +602,13 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
             var skippedFailures = 0;
             DateTime? oldestSkipped = null;
             DateTime? newestSkipped = null;
+            var page = new BackfillPageCursor();
 
             foreach (var record in records)
             {
                 var description = record.Description ?? string.Empty;
                 var fields = ReadCxhFields(record.Id, description, record.Properties);
-                ObserveCxhRecord(record.Id, fields, record.OccurredAtUtc, isBackfill: true, recordId: record.RecordId);
+                ObserveCxhRecord(record.Id, fields, record.OccurredAtUtc, isBackfill: true, recordId: record.RecordId, backfillPage: page);
 
                 if (record.Id == EventId_ShellCore_WebAppStarted)
                 {
@@ -594,7 +651,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                     TenantId = _tenantId,
                     EventType = Constants.EventTypes.AgentTrace,
                     Severity = EventSeverity.Info,
-                    Source = "ShellCoreTracker",
+                    Source = Constants.EventSources.ShellCoreTracker,
                     Phase = EnrollmentPhase.Unknown,
                     Message =
                         $"Shell-Core replay skipped {skippedExits} ESP exit(s) and {skippedFailures} ESP failure(s) " +
@@ -662,6 +719,12 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         // CloudExperienceHost navigation: breadcrumbs and OOBE update page telemetry (D-310)
         // =====================================================================
 
+        /// <summary>The last page started within one backfill batch.</summary>
+        private sealed class BackfillPageCursor
+        {
+            public string Page;
+        }
+
         /// <summary>
         /// Writes one agent.log line per CloudExperienceHost page start/stop and per update-page
         /// event name, so a diagnostics package shows the OOBE navigation. Records of the update
@@ -669,8 +732,16 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
         /// are also reported as <c>oobe_update_page</c> — once across agent runs, by RecordId — and
         /// at the page's live start and stop the registry state behind it as
         /// <c>oobe_update_state</c>. No decision.
+        /// <para>
+        /// A stop (62405) belongs to the page started last. A backfill batch
+        /// (<paramref name="backfillPage"/>) reads records older than the live watcher's, which is
+        /// armed first, so it keeps its own last page; it moves the live watcher's only with a
+        /// record of a higher RecordId — a replayed older start must not take over the next live
+        /// stop, and a first run's live stop still finds the page that started before the agent.
+        /// </para>
         /// </summary>
-        private void ObserveCxhRecord(int eventId, CxhFields fields, DateTime occurredAtUtc, bool isBackfill, long recordId)
+        private void ObserveCxhRecord(int eventId, CxhFields fields, DateTime occurredAtUtc, bool isBackfill, long recordId,
+            BackfillPageCursor backfillPage)
         {
             try
             {
@@ -678,8 +749,15 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                 lock (_stateLock)
                 {
                     if (eventId == EventId_ShellCore_WebAppStarted && fields.Primary != null)
-                        _lastCxhPage = fields.Primary;
-                    page = _lastCxhPage;
+                    {
+                        if (backfillPage != null) backfillPage.Page = fields.Primary;
+                        if (backfillPage == null || (recordId >= 0 && recordId > _lastCxhPageRecordId))
+                        {
+                            _lastCxhPage = fields.Primary;
+                            if (recordId >= 0) _lastCxhPageRecordId = recordId;
+                        }
+                    }
+                    page = backfillPage != null ? backfillPage.Page : _lastCxhPage;
                 }
 
                 var crumb = FormatCxhBreadcrumb(eventId, fields, page);

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/SystemTimelineTracker.cs

@@ -340,7 +340,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                 Timestamp = timeCreatedUtc ?? DateTime.UtcNow,
                 EventType = Constants.EventTypes.SystemClockChanged,
                 Severity = isLargeStep ? EventSeverity.Warning : EventSeverity.Info,
-                Source = "SystemTimelineWatcher",
+                Source = Constants.EventSources.SystemTimelineWatcher,
                 Phase = EnrollmentPhase.Unknown,
                 Message = message,
                 Data = data,
@@ -467,7 +467,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                 Timestamp = timeCreatedUtc ?? DateTime.UtcNow,
                 EventType = Constants.EventTypes.SystemSleepEpisode,
                 Severity = EventSeverity.Info,
-                Source = "SystemTimelineWatcher",
+                Source = Constants.EventSources.SystemTimelineWatcher,
                 Phase = EnrollmentPhase.Unknown,
                 Message = message,
                 Data = data,

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Enrollment/SystemSignals/WindowsUpdateTracker.cs

@@ -405,7 +405,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                 Timestamp = timeCreatedUtc ?? DateTime.UtcNow,
                 EventType = shape.EventType,
                 Severity = shape.Severity,
-                Source = "WindowsUpdateWatcher",
+                Source = Constants.EventSources.WindowsUpdateWatcher,
                 Phase = EnrollmentPhase.Unknown,
                 Message = BuildMessage(eventId, title, updateCount, data),
                 Data = data,
@@ -707,7 +707,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Enrollment.SystemSignals
                     TenantId = _tenantId,
                     EventType = Constants.EventTypes.WindowsUpdateChannelCensus,
                     Severity = EventSeverity.Debug,
-                    Source = "WindowsUpdateWatcher",
+                    Source = Constants.EventSources.WindowsUpdateWatcher,
                     Phase = EnrollmentPhase.Unknown,
                     Message = "Windows Update channel census: OS build changed across restart but no targeted WU events were captured — EventID histogram attached",
                     Data = data,

src/Agent/AutopilotMonitor.Agent.V2.Core/Monitoring/Telemetry/Periodic/AgentSelfMetricsCollector.cs

@@ -215,6 +215,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Monitoring.Telemetry.Periodic
                         data["ime_verified_bytes"] = health.VerifiedBytes;
                         data["ime_pass_max_ms"] = health.PassMaxMs;
                         data["ime_pass_gap_max_ms"] = health.PassGapMaxMs;
+                        data["ime_platform_output_verified"] = health.PlatformOutputVerified;
+                        data["ime_platform_output_corrected"] = health.PlatformOutputCorrected;
                     }
                 }
                 catch (Exception ex)

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/DefaultComponentFactory.cs

@@ -524,14 +524,17 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             // EspTrackingWin32Apps, StatusServiceReports) via snapshot-and-diff. Emits
             // registry_app_state on real changes and app_state_reconciliation when the
             // registry outcome diverges from the IME-log-derived state (= built-in pattern-drift
-            // alarm). Always-on observability host; the tracker probe is read-only.
+            // alarm). Always-on observability host; the tracker probe is read-only. Under the same
+            // root IME saves each platform script's result after reporting the batch: the script
+            // observer checks the tracker's emitted runs against it (script_output_reconciliation).
             hosts.Add(new ImeRegistryAppStateHost(
                 sessionId: sessionId,
                 tenantId: tenantId,
                 logger: logger,
                 ingress: ingress,
                 clock: clock,
-                trackerStateProbe: () => imeLogHost.AllKnownPackageStates));
+                trackerStateProbe: () => imeLogHost.AllKnownPackageStates,
+                scriptRuns: imeLogHost.Tracker.ScriptRuns));
 
             // Deterministic update corroboration — compares the persisted OS build (CurrentBuild.UBR)
             // across agent restarts and emits os_build_changed when it differs (session 7443317c:

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/Hosts/EspAndHelloHost.cs

@@ -142,6 +142,11 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
         /// replayed 62407 cannot be placed in time; see
         /// <c>ShellCoreTracker.ReplayBackfillRecords</c>.
         /// </para>
+        /// <para>
+        /// The first run reads the last hour for the OOBE update page telemetry instead — no
+        /// replay, nothing that reaches the decision engine; see
+        /// <c>ShellCoreTracker.BackfillUpdatePageTelemetry</c>.
+        /// </para>
         /// </summary>
         public void Start()
         {
@@ -149,6 +154,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
 
             if (_espExitBackfillLookbackMinutes > 0)
                 _tracker.BackfillRecentHelloWizardStart(_espExitBackfillLookbackMinutes);
+            else
+                _tracker.BackfillUpdatePageTelemetry(ShellCoreTracker.UpdatePageBackfillLookbackMinutes);
         }
 
         public void Stop() => _tracker.Stop();

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/Hosts/ImeRegistryAppStateHost.cs

@@ -15,9 +15,10 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
 {
     /// <summary>
     /// Hosts the <see cref="ImeRegistryAppStateObserver"/> (registry second pillar, audit
-    /// 2026-08-17): one recursive <see cref="RegistryWatcher"/> on the IME root — all three
-    /// observed surfaces (Win32Apps, EspTrackingWin32Apps, SideCarPolicies\StatusServiceReports)
-    /// live under it — debounced into snapshot-and-diff ticks, plus a 60-s periodic fallback
+    /// 2026-08-17) and the <see cref="ImeRegistryScriptResultObserver"/> (D-316): one recursive
+    /// <see cref="RegistryWatcher"/> on the IME root — every observed surface (Win32Apps,
+    /// EspTrackingWin32Apps, SideCarPolicies\StatusServiceReports, Policies) lives under it —
+    /// debounced into snapshot-and-diff ticks, plus a 60-s periodic fallback
     /// tick. The fallback both evaluates the reconciliation settle-delay when the registry goes
     /// quiet AND keeps the pillar alive if the watcher fails to arm (poll-only degraded mode,
     /// announced once via <c>collector_degraded</c>). Always-on observability host, no config
@@ -31,6 +32,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
         private static readonly TimeSpan PeriodicInterval = TimeSpan.FromSeconds(60);
 
         private readonly ImeRegistryAppStateObserver _observer;
+        // Platform-script results under the same root (D-316); null when no run register was supplied.
+        private readonly ImeRegistryScriptResultObserver? _scriptObserver;
         private readonly InformationalEventPost _post;
         private readonly AgentLogger? _logger;
         private readonly string _sessionId;
@@ -47,7 +50,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             AgentLogger? logger,
             ISignalIngressSink ingress,
             IClock clock,
-            Func<IReadOnlyList<AppPackageState>>? trackerStateProbe)
+            Func<IReadOnlyList<AppPackageState>>? trackerStateProbe,
+            PlatformScriptRunRegister? scriptRuns = null)
         {
             if (ingress == null) throw new ArgumentNullException(nameof(ingress));
             if (clock == null) throw new ArgumentNullException(nameof(clock));
@@ -56,6 +60,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             _logger = logger;
             _post = new InformationalEventPost(ingress, clock);
             _observer = new ImeRegistryAppStateObserver(_post, logger, clock, trackerStateProbe);
+            if (scriptRuns != null) _scriptObserver = new ImeRegistryScriptResultObserver(scriptRuns, _post, logger, clock);
         }
 
         public void Start()
@@ -63,6 +68,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             // Baseline immediately: pre-existing registry state must be captured silently
             // BEFORE the first change edge, or stale entries would replay as fresh events.
             _observer.Tick("baseline");
+            _scriptObserver?.Tick("baseline");
 
             try
             {
@@ -120,6 +126,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             try
             {
                 _observer.Tick(reason);
+                _scriptObserver?.Tick(reason);
             }
             catch (Exception ex)
             {

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/Hosts/WindowsUpdateWatcherHost.cs

@@ -197,7 +197,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
                     TenantId = _tenantId,
                     EventType = SharedConstants.EventTypes.WindowsUpdateActivitySummary,
                     Severity = EventSeverity.Debug,
-                    Source = "WindowsUpdateWatcher",
+                    Source = SharedConstants.EventSources.WindowsUpdateWatcher,
                     Phase = EnrollmentPhase.Unknown,
                     Message = $"Update activity counted instead of listed: {total} event(s) " +
                         "(Store, Defender and other non-OS updates, repeated scan results, servicing of non-OS packages)",
@@ -223,7 +223,7 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             _ingress.Post(
                 kind: DecisionSignalKind.OsUpdateActivity,
                 occurredAtUtc: DateTime.SpecifyKind(occurredAtUtc, DateTimeKind.Utc),
-                sourceOrigin: source == "servicing" ? "ServicingWatcher" : "WindowsUpdateWatcher",
+                sourceOrigin: source == "servicing" ? SharedConstants.EventSources.ServicingWatcher : SharedConstants.EventSources.WindowsUpdateWatcher,
                 evidence: new Evidence(
                     kind: EvidenceKind.Raw,
                     identifier: $"os-update-activity:{source}",

src/Agent/AutopilotMonitor.Agent.V2.Core/Orchestration/SignalActivityClassifier.cs

@@ -92,6 +92,9 @@ namespace AutopilotMonitor.Agent.V2.Core.Orchestration
             SharedConstants.EventTypes.ImePatternHits,
             // Bookkeeping of runs that were deliberately not reported as activity.
             SharedConstants.EventTypes.ScriptRecurrenceSummary,
+            // A correction of an already reported script run from IME's saved result (D-316):
+            // registry observation after the fact, not progress.
+            SharedConstants.EventTypes.ScriptOutputReconciliation,
             // Same for the update watchers' tally of Store/Defender/other update events (D-310):
             // emitted on stop, never progress. Windows/.NET update steps stay activity.
             SharedConstants.EventTypes.WindowsUpdateActivitySummary,

src/Agent/AutopilotMonitor.Agent.V2.Core/SignalAdapters/ImeLogTrackerAdapter.cs

@@ -1263,6 +1263,8 @@ namespace AutopilotMonitor.Agent.V2.Core.SignalAdapters
             // logged its result line before the deadline). Lets the UI/MCP flag fallback-grounded
             // platform-script completions. Platform scripts only — null for health scripts.
             if (!string.IsNullOrEmpty(script.ResultSource)) data["resultSource"] = script.ResultSource!;
+            // The run a later script_output_reconciliation corrects names it by this id (platform only).
+            if (!string.IsNullOrEmpty(script.RunId)) data["runId"] = script.RunId!;
             if (!string.IsNullOrEmpty(script.ComplianceResult)) data["complianceResult"] = script.ComplianceResult!;
             if (script.RemediationStatus.HasValue) data["remediationStatus"] = script.RemediationStatus.Value.ToString(culture);
             if (script.TargetType.HasValue) data["targetType"] = script.TargetType.Value.ToString(culture);

src/Agent/AutopilotMonitor.Agent.V2.Core/Termination/EnrollmentTerminationHandler.cs

@@ -599,6 +599,8 @@ namespace AutopilotMonitor.Agent.V2.Core.Termination
                     ["verifiedBytes"] = health.VerifiedBytes,
                     ["passMaxMs"] = health.PassMaxMs,
                     ["passGapMaxMs"] = health.PassGapMaxMs,
+                    ["platformOutputVerified"] = health.PlatformOutputVerified,
+                    ["platformOutputCorrected"] = health.PlatformOutputCorrected,
                     ["agentVersion"] = _agentVersion ?? string.Empty,
                 };
                 if (!string.IsNullOrEmpty(health.ImeAgentVersion))

src/Backend/AutopilotMonitor.Functions.Tests/OobeUpdateRuleTests.cs

@@ -0,0 +1,481 @@
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared.DataAccess;
+using AutopilotMonitor.Shared.Models;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// The OOBE quality update page (oobe_update_page, D-310) — pins the built-in analyze rules for
+/// the update that did not happen:
+///   - ANALYZE-DEV-013: the page reported a failed download or install and no install success
+///     (field shapes e7551b82, cb1992b8). Only the explicit failure names count: an update that
+///     installed logs downloadInstallFailureHelper and a start timeout too (e4ecd6f8).
+///   - ANALYZE-DEV-014: nothing offered to an out-of-date device whose page counts an earlier
+///     failure, without a failure in this session (b2d9f12c).
+///   - ANALYZE-DEV-015: the scan started and the page ended without a scan result (c5b20dfa).
+/// Every absence condition is vetoed by the agent's names_capped marker. Sequences follow the
+/// field sessions of 2026-10-03..05 (synthetic times, no customer data); a session never fires
+/// two of the three.
+/// </summary>
+public class OobeUpdateRuleTests
+{
+    private const string TenantId  = "a1b2c3d4-e5f6-7890-abcd-ef1234567890";
+    private const string SessionId = "11111111-2222-3333-4444-555555555555";
+
+    private static readonly DateTime T0 = new(2026, 10, 3, 16, 56, 59, DateTimeKind.Utc);
+
+    private const string DownloadFailed = "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError";
+    private const string InstallFailed = "SdxWebAppCloudNDUP_processStatusChangeFromHandler_installFailedError";
+    private const string CommitFailed = "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure";
+
+    private static readonly string[] RuleIds = { "ANALYZE-DEV-013", "ANALYZE-DEV-014", "ANALYZE-DEV-015" };
+
+    // ── the rules ───────────────────────────────────────────────────────────
+
+    [Theory]
+    [InlineData("ANALYZE-DEV-013")]
+    [InlineData("ANALYZE-DEV-014")]
+    [InlineData("ANALYZE-DEV-015")]
+    public void Rules_are_enabled_warnings_that_never_fail_the_session(string ruleId)
+    {
+        var rule = Rule(ruleId);
+        Assert.True(rule.Enabled);
+        Assert.Equal("warning", rule.Severity);
+        Assert.Equal("device", rule.Category);
+        Assert.False(rule.MarkSessionAsFailedDefault); // the enrollment continues without the update
+    }
+
+    // ── ANALYZE-DEV-013: failed ─────────────────────────────────────────────
+
+    [Fact]
+    public async Task DEV_013_fires_on_a_failed_download_and_names_the_failure()
+    {
+        var outcome = await RunAsync(FailedDownload());
+
+        var result = Assert.Single(outcome.Results);
+        Assert.Equal("ANALYZE-DEV-013", result.RuleId);
+        Assert.Equal(DownloadFailed, Value(result, "update_failure"));   // {{update_failure}}
+        Assert.Equal("fail", Value(result, "update_page_failed"));
+        Assert.Equal(85, result.ConfidenceScore);
+    }
+
+    [Fact]
+    public async Task DEV_013_fires_when_the_update_is_skipped_after_the_failure()
+    {
+        var outcome = await RunAsync(FailureThenSkip());
+
+        var result = Assert.Single(outcome.Results);
+        Assert.Equal("ANALYZE-DEV-013", result.RuleId);
+        Assert.Equal(DownloadFailed, Value(result, "update_failure"));
+        Assert.Equal("CloudNDUPSkipDownloadInstallButtonClicked", Value(result, "update_skipped"));
+    }
+
+    [Theory]
+    [InlineData(InstallFailed)]
+    [InlineData(CommitFailed)]
+    public async Task DEV_013_fires_on_every_explicit_failure_name(string failureName)
+    {
+        var events = Visit(days: 120, previousFailures: 0);
+        events.AddRange(new[] { Name("ExpeditedUpdate_getUpdateResultsSucceeded"), Name(failureName), PageStop("OobeNDUP", "fail") });
+
+        var result = Assert.Single((await RunAsync(events)).Results);
+        Assert.Equal(failureName, Value(result, "update_failure"));
+    }
+
+    [Theory]
+    [InlineData(true)]
+    [InlineData(false)]
+    public async Task DEV_013_stays_silent_on_an_update_that_installed_despite_the_failure_helper(bool buildChangeObserved)
+    {
+        // Field shape e4ecd6f8: the failure helper and a start timeout after "restart required",
+        // then the update installed — with or without the build change on record.
+        var events = InstalledDespiteFailureHelper();
+        if (!buildChangeObserved) events.RemoveAll(e => e.EventType == "os_build_changed");
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    [Fact]
+    public async Task DEV_013_stays_silent_when_a_retry_installed_the_update()
+    {
+        var events = FailedDownload();
+        events.AddRange(new[]
+        {
+            PageStart("OobeNDUP"),
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Name("SdxWebAppCloudNDUP_processStatusChangeFromHandler_installSucceededRebootRequired_lcu"),
+        });
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    [Fact]
+    public async Task DEV_013_is_vetoed_by_an_os_build_change()
+    {
+        var events = FailedDownload();
+        events.Add(OsBuildChanged());
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    // ── ANALYZE-DEV-014: not offered after an earlier failure ───────────────
+
+    [Fact]
+    public async Task DEV_014_fires_when_nothing_is_offered_after_an_earlier_failure()
+    {
+        var outcome = await RunAsync(NothingOfferedAfterFailure());
+
+        var result = Assert.Single(outcome.Results);
+        Assert.Equal("ANALYZE-DEV-014", result.RuleId);
+        Assert.Equal("137", Value(result, "days_out_of_date"));   // {{days_out_of_date}}
+        Assert.Equal("1", Value(result, "previous_failures"));    // {{previous_failures}}
+    }
+
+    [Theory]
+    [InlineData(0, 1)]   // the device is current: nothing to offer
+    [InlineData(137, 0)] // no earlier failure on record
+    public async Task DEV_014_stays_silent_without_both_the_backlog_and_the_earlier_failure(int days, int previousFailures)
+    {
+        var events = Visit(days, previousFailures);
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI", "false"),
+            PageStop("OobeNDUP", "cancel"),
+        });
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    // ── ANALYZE-DEV-015: scan without a result ──────────────────────────────
+
+    [Fact]
+    public async Task DEV_015_fires_when_the_page_ends_without_a_scan_result()
+    {
+        var outcome = await RunAsync(ScanWithoutResult());
+
+        var result = Assert.Single(outcome.Results);
+        Assert.Equal("ANALYZE-DEV-015", result.RuleId);
+        Assert.Equal("438", Value(result, "days_out_of_date"));
+        Assert.Equal("page_stopped", Value(result, "update_page_ended"));
+    }
+
+    [Fact]
+    public async Task DEV_015_stays_silent_while_the_page_still_runs()
+    {
+        // The session ended during the scan: no page end, so no claim that the page gave up.
+        var events = ScanWithoutResult();
+        events.RemoveAll(e => e.EventType == "oobe_update_page" && (string)e.Data["cxhEvent"] == "page_stopped");
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    [Fact]
+    public async Task DEV_015_stays_silent_when_the_agent_missed_the_scan_start()
+    {
+        // A late agent sees the page end but not the scan: the missing result proves nothing.
+        var events = ScanWithoutResult();
+        events.RemoveAll(e => e.EventType == "oobe_update_page" && (e.Data.TryGetValue("name", out var n) ? (string)n : "").StartsWith("ExpeditedUpdate_startWUScan"));
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    // ── shared vetoes and the sessions that fire nothing ────────────────────
+
+    [Theory]
+    [MemberData(nameof(FiringShapes))]
+    public async Task The_names_capped_marker_vetoes_every_rule(string shape)
+    {
+        // Once the agent capped the page's names, a missing success or scan result proves nothing.
+        var events = Shapes[shape]();
+        events.Add(NamesCapped());
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    [Fact]
+    public async Task A_page_the_policy_switched_off_fires_nothing()
+    {
+        var events = new List<EnrollmentEvent>
+        {
+            PageStart("OobeNDUP"),
+            Name("ExpeditedUpdate_isNDUPAllowedByCSPSucceeded", "false"),
+            PageStop("OobeNDUP", "cancel"),
+            PageStart("RebootNDUP"),
+            PageStop("RebootNDUP", "success"),
+        };
+
+        Assert.Empty((await RunAsync(events)).Results);
+    }
+
+    [Fact]
+    public async Task An_installed_update_fires_nothing()
+    {
+        Assert.Empty((await RunAsync(Installed())).Results);
+    }
+
+    [Theory]
+    [MemberData(nameof(AllShapes))]
+    public async Task No_session_fires_more_than_one_of_the_three(string shape)
+    {
+        var outcome = await RunAsync(Shapes[shape]());
+
+        Assert.True(outcome.Results.Count <= 1, $"{shape}: {string.Join(", ", outcome.Results.Select(r => r.RuleId))}");
+    }
+
+    // ── session shapes (field sessions, synthetic times) ────────────────────
+
+    private static readonly Dictionary<string, Func<List<EnrollmentEvent>>> Shapes = new()
+    {
+        ["failed_download"] = FailedDownload,
+        ["failure_then_skip"] = FailureThenSkip,
+        ["installed_despite_failure_helper"] = InstalledDespiteFailureHelper,
+        ["nothing_offered_after_failure"] = NothingOfferedAfterFailure,
+        ["scan_without_result"] = ScanWithoutResult,
+        ["installed"] = Installed,
+    };
+
+    public static IEnumerable<object[]> AllShapes() => Shapes.Keys.Select(k => new object[] { k });
+
+    public static IEnumerable<object[]> FiringShapes() =>
+        new[] { "failed_download", "failure_then_skip", "nothing_offered_after_failure", "scan_without_result" }
+            .Select(k => new object[] { k });
+
+    /// <summary>The names every visit logs before its scan.</summary>
+    private static List<EnrollmentEvent> Visit(int days, int previousFailures) => new()
+    {
+        PageStart("OobeNDUP"),
+        Name("ExpeditedUpdate_isNDUPAllowedByCSPSucceeded", "true"),
+        Name("ExpeditedUpdate_getDaysOutOfDateSucceeded", days.ToString()),
+        Name("SdxWebAppCloudNDUP_initialize_NDUPInstallCanceledInOptOut", "false"),
+        Name("SdxWebAppCloudNDUP_initialize_NDUPDownloadInstallPreviousFailureCount", previousFailures.ToString()),
+        Name("ExpeditedUpdate_startWUScanStarted"),
+        Name("ExpeditedUpdate_startWUScanStartedSuccedded"),
+    };
+
+    /// <summary>e7551b82: only the servicing stack staged, the download failed after 25 min; the second visit found nothing to offer.</summary>
+    private static List<EnrollmentEvent> FailedDownload()
+    {
+        var events = Visit(days: 136, previousFailures: 0);
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsStarted"),
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI"), // a list: no safe value
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Name(DownloadFailed),
+            Name(CommitFailed),
+            Name("SdxWebAppCloudNDUP_downloadInstallFailureHelper"),
+            PageStop("OobeNDUP", "fail"),
+            PageStart("RebootNDUP"),
+        });
+        events.AddRange(Visit(days: 137, previousFailures: 1));
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI", "false"),
+            PageStop("OobeNDUP", "cancel"),
+            PageStart("RebootNDUP"),
+            PageStop("RebootNDUP", "success"),
+        });
+        return events;
+    }
+
+    /// <summary>cb1992b8: visit 1 failed; visit 2 downloaded again and someone selected Skip before the install.</summary>
+    private static List<EnrollmentEvent> FailureThenSkip()
+    {
+        var events = Visit(days: 438, previousFailures: 0);
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Name(DownloadFailed),
+            Name(CommitFailed),
+            Name(InstallFailed),
+            PageStop("OobeNDUP", "fail"),
+            PageStart("RebootNDUP"),
+        });
+        events.AddRange(Visit(days: 438, previousFailures: 1));
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI"),
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Name("CloudNDUPOptoutLinkClicked", "0"),
+            Name("SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateUSOProgressBar_DownloadPhase_progress100"),
+            Name("SdxWebAppCloudNDUP_manageProgressBars_waitingForInstallStartError"),
+            Name("CloudNDUPSkipDownloadInstallButtonClicked", "0"),
+            PageStop("OobeNDUP", "cancel"),
+            PageStart("RebootNDUP"),
+            PageStop("RebootNDUP", "success"),
+        });
+        return events;
+    }
+
+    /// <summary>e4ecd6f8: the failure helper and a start timeout after "restart required" — the update installed after three restarts.</summary>
+    private static List<EnrollmentEvent> InstalledDespiteFailureHelper()
+    {
+        var events = Visit(days: 99, previousFailures: 0);
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Name("SdxWebAppCloudNDUP_updateUSOProgressBar_installPhase_progress100"),
+            Name("SdxWebAppCloudNDUP_downloadInstallFailureHelper"),
+            Name("SdxWebAppCloudNDUP_startEventArrivalTimeout_TimerExpired"),
+            PageStart("RebootNDUP"),
+            OsBuildChanged(),
+            PageStart("OobeNDUP"),
+            PageStop("OobeNDUP", "success"),
+        });
+        return events;
+    }
+
+    /// <summary>b2d9f12c: the same device the next day — out of date, an earlier failure on record, nothing offered.</summary>
+    private static List<EnrollmentEvent> NothingOfferedAfterFailure()
+    {
+        var events = Visit(days: 137, previousFailures: 1);
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsStarted"),
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI", "false"),
+            Name("SdxWebAppCloudNDUP_exit_appResult"),
+            PageStop("OobeNDUP", "cancel"),
+            PageStart("RebootNDUP"),
+            PageStop("RebootNDUP", "success"),
+        });
+        return events;
+    }
+
+    /// <summary>c5b20dfa: 438 days behind; the page ended two minutes after the scan started, without a result.</summary>
+    private static List<EnrollmentEvent> ScanWithoutResult()
+    {
+        var events = Visit(days: 438, previousFailures: 0);
+        events.AddRange(new[]
+        {
+            Name("SdxWebAppCloudNDUP_processStatusChangeFromHandler_installSucceededNoReboot"), // the language check, every visit
+            Name("SdxWebAppCloudNDUP_exit_appResult"),
+            PageStop("OobeNDUP", "cancel"),
+            PageStart("RebootNDUP"),
+            PageStop("RebootNDUP", "success"),
+        });
+        return events;
+    }
+
+    /// <summary>6a7d241d: downloaded, installed, restarted.</summary>
+    private static List<EnrollmentEvent> Installed()
+    {
+        var events = Visit(days: 120, previousFailures: 0);
+        events.AddRange(new[]
+        {
+            Name("ExpeditedUpdate_getUpdateResultsSucceeded"),
+            Name("SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI"),
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Name("SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded"),
+            Name("SdxWebAppCloudNDUP_processStatusChangeFromHandler_installSucceededRebootRequired"),
+            Name("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncSucceeded"),
+            Name("SdxWebAppCloudNDUP_rebootCountdown_starting"),
+            PageStart("RebootNDUP"),
+            OsBuildChanged(),
+        });
+        return events;
+    }
+
+    // ── event builders — mirror the agent's OobeUpdateTelemetry payload ─────
+
+    private static long _seq;
+
+    private static EnrollmentEvent Evt(string eventType, Dictionary<string, object> data)
+    {
+        var seq = Interlocked.Increment(ref _seq);
+        return new EnrollmentEvent
+        {
+            EventId = Guid.NewGuid().ToString(),
+            TenantId = TenantId,
+            SessionId = SessionId,
+            EventType = eventType,
+            Timestamp = T0.AddSeconds(seq),
+            Sequence = seq,
+            Data = data,
+        };
+    }
+
+    private static Dictionary<string, object> PageData(string cxhEvent, int windowsEventId) => new()
+    {
+        ["cxhEvent"] = cxhEvent,
+        ["windowsEventId"] = windowsEventId,
+        ["backfill"] = false,
+        ["occurrence"] = 1,
+    };
+
+    private static EnrollmentEvent PageStart(string page)
+    {
+        var data = PageData("page_started", 62404);
+        data["page"] = page;
+        return Evt("oobe_update_page", data);
+    }
+
+    private static EnrollmentEvent PageStop(string page, string result)
+    {
+        var data = PageData("page_stopped", 62405);
+        data["page"] = page;
+        data["result"] = result;
+        return Evt("oobe_update_page", data);
+    }
+
+    private static EnrollmentEvent Name(string name, string? value = null)
+    {
+        var data = PageData("event_name", value == null ? 62406 : 62407);
+        data["name"] = name;
+        if (value != null) data["value"] = value;
+        return Evt("oobe_update_page", data);
+    }
+
+    private static EnrollmentEvent NamesCapped()
+    {
+        var data = PageData("names_capped", 0);
+        data.Remove("windowsEventId");
+        data.Remove("occurrence");
+        data["limit"] = 150;
+        return Evt("oobe_update_page", data);
+    }
+
+    private static EnrollmentEvent OsBuildChanged() => Evt("os_build_changed", new Dictionary<string, object>
+    {
+        ["previousBuild"] = "26200.8037",
+        ["currentBuild"] = "26200.8655",
+    });
+
+    // ── harness (as WindowsUpdateRuleTests) ─────────────────────────────────
+
+    private static AnalyzeRule Rule(string ruleId) => BuiltInAnalyzeRules.GetAll().First(r => r.RuleId == ruleId);
+
+    private static string Value(RuleResult result, string signal)
+    {
+        var evidence = Assert.IsType<Dictionary<string, object>>(result.MatchedConditions[signal]);
+        return evidence["value"]?.ToString() ?? string.Empty;
+    }
+
+    private static async Task<AnalysisOutcome> RunAsync(List<EnrollmentEvent> events)
+    {
+        var rules = RuleIds.Select(Rule).ToList();
+
+        var ruleRepo = new Mock<IRuleRepository>();
+        ruleRepo.Setup(r => r.GetAnalyzeRulesAsync("global")).ReturnsAsync(rules);
+        ruleRepo.Setup(r => r.GetAnalyzeRulesAsync(TenantId)).ReturnsAsync(new List<AnalyzeRule>());
+        ruleRepo.Setup(r => r.GetRuleStatesAsync(It.IsAny<string>())).ReturnsAsync(new Dictionary<string, RuleState>());
+        ruleRepo.Setup(r => r.GetRuleResultsAsync(It.IsAny<string>(), It.IsAny<string>())).ReturnsAsync(new List<RuleResult>());
+
+        var sessionRepo = new Mock<ISessionRepository>();
+        sessionRepo.Setup(s => s.GetSessionEventsStrictAsync(TenantId, SessionId, It.IsAny<int>())).ReturnsAsync(events);
+
+        var ruleService = new AnalyzeRuleService(ruleRepo.Object, NullLogger<AnalyzeRuleService>.Instance);
+        var engine = new RuleEngine(ruleService, ruleRepo.Object, sessionRepo.Object, NullLogger<OobeUpdateRuleTests>.Instance);
+
+        return await engine.AnalyzeSessionAsync(TenantId, SessionId);
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/PlatformStatsPublishTests.cs

@@ -0,0 +1,45 @@
+using System.Globalization;
+using AutopilotMonitor.Functions.Services;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// The versioned platform-stats file is served immutable for a year, so every publish must write
+/// a new name. Maintenance publishes every 2 hours; the per-day name it used to write was rewritten
+/// up to 12 times a day, and caches kept the first copy of the day.
+/// </summary>
+public class PlatformStatsPublishTests
+{
+    private static readonly DateTime Publish = new(2026, 10, 3, 6, 0, 4, DateTimeKind.Utc);
+
+    [Fact]
+    public void Versioned_file_name_carries_the_publish_instant_to_the_second()
+    {
+        Assert.Equal("platform-stats.2026-10-03T060004Z.json", MaintenanceService.PlatformStatsVersionedFileName(Publish));
+    }
+
+    [Fact]
+    public void Two_publishes_of_one_day_get_different_names()
+    {
+        var early = MaintenanceService.PlatformStatsVersionedFileName(new DateTime(2026, 10, 3, 2, 0, 3, DateTimeKind.Utc));
+        var later = MaintenanceService.PlatformStatsVersionedFileName(new DateTime(2026, 10, 3, 4, 0, 3, DateTimeKind.Utc));
+
+        Assert.NotEqual(early, later);
+    }
+
+    [Fact]
+    public void Versioned_file_name_ignores_the_current_culture()
+    {
+        var previous = CultureInfo.CurrentCulture;
+        try
+        {
+            // th-TH counts years in the Buddhist era (2569 for 2026).
+            CultureInfo.CurrentCulture = new CultureInfo("th-TH");
+            Assert.Equal("platform-stats.2026-10-03T060004Z.json", MaintenanceService.PlatformStatsVersionedFileName(Publish));
+        }
+        finally
+        {
+            CultureInfo.CurrentCulture = previous;
+        }
+    }
+}

src/Backend/AutopilotMonitor.Functions.Tests/ScriptOutputReconciliationClassificationTests.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// D-316: the agent corrects an already reported platform run from IME's saved result with a
+/// script_output_reconciliation. It is observation of an earlier run: it never heals a Stalled session and never
+/// counts as another script run.
+/// </summary>
+public class ScriptOutputReconciliationClassificationTests
+{
+    private static readonly DateTime At = new(2026, 10, 3, 20, 59, 8, DateTimeKind.Utc);
+
+    [Fact]
+    public void A_correction_alone_is_no_real_activity_and_no_script_run()
+    {
+        var classification = EventIngestProcessor.ClassifyEvents(new List<EnrollmentEvent>
+        {
+            Event(Constants.EventTypes.ScriptOutputReconciliation, new Dictionary<string, object> { ["scriptType"] = "platform", ["runId"] = "run-1", ["outcome"] = "foreign" }),
+        });
+
+        Assert.False(classification.HasNonPeriodicRealEvent);
+        Assert.Equal(0, classification.PlatformScriptCount);
+    }
+
+    [Fact]
+    public void The_corrected_run_counts_once_as_a_platform_script()
+    {
+        var classification = EventIngestProcessor.ClassifyEvents(new List<EnrollmentEvent>
+        {
+            Event("script_failed", new Dictionary<string, object> { ["scriptType"] = "platform", ["runId"] = "run-1", ["exitCode"] = "1" }),
+            Event(Constants.EventTypes.ScriptOutputReconciliation, new Dictionary<string, object> { ["scriptType"] = "platform", ["runId"] = "run-1", ["outcome"] = "foreign" }),
+        });
+
+        Assert.True(classification.HasNonPeriodicRealEvent);
+        Assert.Equal(1, classification.PlatformScriptCount);
+    }
+
+    private static EnrollmentEvent Event(string eventType, Dictionary<string, object> data) => new()
+    {
+        EventId = Guid.NewGuid().ToString(),
+        Timestamp = At,
+        EventType = eventType,
+        Source = "RegistryScriptResult",
+        Data = data,
+    };
+}

src/Backend/AutopilotMonitor.Functions.Tests/SessionAnchorSourceTests.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using AutopilotMonitor.Functions.Services;
+using AutopilotMonitor.Shared;
+using AutopilotMonitor.Shared.Models;
+using Xunit;
+
+namespace AutopilotMonitor.Functions.Tests;
+
+/// <summary>
+/// Backfilled environment observations never set the session start (D-315). Since agent 2.0.1473
+/// the update and servicing watchers deliver rows with their original event time up to 60 min
+/// before the agent started; anchoring on them stretched StartedAt by 22 min at the median
+/// (p90 57 min). Source strings are the persisted wire values, spelled out on purpose.
+/// </summary>
+public class SessionAnchorSourceTests
+{
+    private static readonly DateTime AgentStart = new(2026, 10, 3, 9, 6, 46, DateTimeKind.Utc);
+
+    [Theory]
+    [InlineData("SystemTimelineWatcher")]
+    [InlineData("WindowsUpdateWatcher")]
+    [InlineData("ServicingWatcher")]
+    [InlineData("ShellCoreTracker")]   // the update page, read back an hour on an agent's first run
+    public void Backfill_sources_are_not_anchor_eligible(string source)
+    {
+        Assert.False(Constants.EventSources.IsSessionAnchorEligible(source));
+    }
+
+    [Theory]
+    [InlineData("ImeLogTracker")]
+    [InlineData("Agent")]
+    [InlineData("MdmRebootPolicyWatcher")]
+    [InlineData("EspAndHelloTracker")]   // the ESP and Hello signals from the same Shell-Core log
+    [InlineData("windowsupdatewatcher")] // ordinal: a differently cased source is not the watcher
+    [InlineData(null)]                    // legacy row without a source
+    public void Activity_sources_are_anchor_eligible(string? source)
+    {
+        Assert.True(Constants.EventSources.IsSessionAnchorEligible(source));
+    }
+
+    [Fact]
+    public void Ingest_batch_anchors_on_the_first_activity_not_on_backfilled_update_rows()
+    {
+        // Shape of session 0f1d1f58: update scans and CBS servicing backfilled from before the
+        // IME replay, a clock step even earlier, then IME replay, agent start, a live update row.
+        var firstImeLine = AgentStart.AddMinutes(-10);
+        var liveUpdate = AgentStart.AddMinutes(25);
+        var events = new List<EnrollmentEvent>
+        {
+            Event(AgentStart.AddMinutes(-16), "system_clock_changed", "SystemTimelineWatcher"),
+            Event(AgentStart.AddMinutes(-15), "windows_update_started", "WindowsUpdateWatcher"),
+            Event(AgentStart.AddMinutes(-14), "windows_update_servicing", "ServicingWatcher"),
+            Event(firstImeLine, "ime_agent_version", "ImeLogTracker"),
+            Event(AgentStart, "agent_started", "Agent"),
+            Event(liveUpdate, "windows_update_started", "WindowsUpdateWatcher"),
+        };
+
+        var classification = EventIngestProcessor.ClassifyEvents(events);
+
+        Assert.Equal(firstImeLine, classification.EarliestEventTimestamp);
+        // The latest timestamp still counts every row: a live update row is a real agent report.
+        Assert.Equal(liveUpdate, classification.LatestEventTimestamp);
+    }
+
+    [Fact]
+    public void Ingest_batch_of_only_backfilled_rows_carries_no_anchor()
+    {
+        var events = new List<EnrollmentEvent>
+        {
+            Event(AgentStart.AddMinutes(-50), "windows_update_started", "WindowsUpdateWatcher"),
+            Event(AgentStart.AddMinutes(-40), "windows_update_servicing", "ServicingWatcher"),
+        };
+
+        var classification = EventIngestProcessor.ClassifyEvents(events);
+
+        Assert.Null(classification.EarliestEventTimestamp);
+        Assert.Equal(AgentStart.AddMinutes(-40), classification.LatestEventTimestamp);
+    }
+
+    private static EnrollmentEvent Event(DateTime timestamp, string eventType, string source) => new()
+    {
+        EventId = Guid.NewGuid().ToString(),
+        Timestamp = timestamp,
+        EventType = eventType,
+        Source = source,
+    };
+}

src/Backend/AutopilotMonitor.Functions.Tests/SessionStartedAtBackwardShiftGuardTests.cs

@@ -104,10 +104,14 @@ public class SessionStartedAtBackwardShiftGuardTests
     // =========================== system-timeline rows are not session anchors ====
 
     [Fact]
-    public void IsSessionAnchorEligible_excludes_system_timeline_watcher_rows()
+    public void IsSessionAnchorEligible_excludes_backfilled_environment_rows()
     {
         Assert.False(TableStorageService.IsSessionAnchorEligible(
             new TableEntity("p", "r") { ["Source"] = "SystemTimelineWatcher" }));
+        Assert.False(TableStorageService.IsSessionAnchorEligible(
+            new TableEntity("p", "r") { ["Source"] = "WindowsUpdateWatcher" }));
+        Assert.False(TableStorageService.IsSessionAnchorEligible(
+            new TableEntity("p", "r") { ["Source"] = "ServicingWatcher" }));
         Assert.True(TableStorageService.IsSessionAnchorEligible(
             new TableEntity("p", "r") { ["Source"] = "ImeLogTracker" }));
         Assert.True(TableStorageService.IsSessionAnchorEligible(
@@ -140,6 +144,29 @@ public class SessionStartedAtBackwardShiftGuardTests
         Assert.Equal((int)(lastEvent - firstActivity).TotalSeconds, harness.Written!.GetInt32("DurationSeconds"));
     }
 
+    [Fact]
+    public async Task Pending_duration_skips_backfilled_update_rows_and_anchors_on_activity()
+    {
+        // D-315: update scans and CBS servicing backfilled with their event time up to 60 min
+        // before the agent started were the partition's earliest rows and re-anchored StartedAt.
+        var firstActivity = StartedAt.AddMinutes(-5);
+        var lastEvent = StartedAt.AddMinutes(70);
+        var harness = new Harness(SessionRow(), eventRows: new[]
+        {
+            EventRow(StartedAt.AddMinutes(-55), sequence: 27, source: "WindowsUpdateWatcher"),
+            EventRow(StartedAt.AddMinutes(-50), sequence: 34, source: "ServicingWatcher"),
+            EventRow(firstActivity, sequence: 2, source: "ImeLogTracker"),
+        });
+
+        var ok = await harness.Sut.UpdateSessionStatusAsync(
+            TenantId, SessionId, SessionStatus.Pending, VerdictPaths.AgentWhiteGlovePending,
+            latestEventTimestamp: lastEvent);
+
+        Assert.True(ok);
+        Assert.NotNull(harness.Written);
+        Assert.Equal((int)(lastEvent - firstActivity).TotalSeconds, harness.Written!.GetInt32("DurationSeconds"));
+    }
+
     private static TableEntity EventRow(DateTime occurredUtc, int sequence, string source) =>
         new($"{TenantId}_{SessionId}", $"{occurredUtc:yyyyMMddHHmmssfff}_{sequence:D10}")
         {

src/Backend/AutopilotMonitor.Functions.Tests/SharedManifestParityTests.cs

@@ -90,6 +90,10 @@ public sealed class SharedManifestParityTests
             ["annotationVerdicts"] = AnnotationVerdicts.All,
             // Install channels of the app rows (AppInstallSummary.Source and the per-app DTOs).
             ["appInstallSources"] = AppInstallSources.All,
+            // Event sources whose rows never set a session's start; the portal's session duration applies them.
+            ["sessionAnchorIneligibleSources"] = Constants.EventSources.SessionAnchorIneligible,
+            // How an OOBE quality update ended (OsUpdateSpan.Outcome in the time attribution).
+            ["osUpdateOutcomes"] = OsUpdateOutcomes.All,
             // Community rule submissions: kinds, effective statuses (incl. the derived "published"),
             // attribution modes and reviewer decisions — the MCP tool schemas enumerate these.
             ["ruleSubmissionKinds"] = RuleSubmissionKinds.All,

src/Backend/AutopilotMonitor.Functions.Tests/TimeAttributionOsUpdateTests.cs

@@ -6,10 +6,12 @@ namespace AutopilotMonitor.Functions.Tests;
 
 /// <summary>
 /// Golden fixtures for the OOBE quality update in the time attribution (AttributionVersion 4,
-/// D-314): <c>os_update</c> from the update page start whose visit holds update evidence to the
-/// last update evidence before the user is back, then — after a restart — <c>awaiting_sign_in</c>
-/// until the user is back. Sequences follow the field sessions of 2026-10-02 (synthetic times, no
-/// customer data). EVERY fixture asserts the exact-partition invariant.
+/// D-314; v5): <c>os_update</c> from the update page start whose visit holds update evidence — or,
+/// when the agent missed the start, from the update's first evidence — to the last update evidence
+/// before the user is back, then — after a restart — <c>awaiting_sign_in</c> until the user is back;
+/// the latest outcome evidence names the outcome. Sequences follow the field sessions of
+/// 2026-10-02..05 (synthetic times, no customer data). EVERY fixture asserts the exact-partition
+/// invariant.
 /// </summary>
 public class TimeAttributionOsUpdateTests
 {
@@ -131,7 +133,7 @@ public class TimeAttributionOsUpdateTests
         var b = TimeAttributionCalculator.Compute(Input(LongUpdateWithSecondVisit(), At(125), 7500))!;
 
         AssertExactPartition(b);
-        Assert.Equal(4, b.AttributionVersion);
+        Assert.Equal(TimeAttributionCalculator.CurrentVersion, b.AttributionVersion);
         Assert.Equal(120, Total(b, TimeAttributionSegments.DevicePrep));
         Assert.Equal(18 * 60 + 5, Total(b, TimeAttributionSegments.EspApps));             // +2m → page start
         Assert.Equal(100 * 60 + 31, Total(b, TimeAttributionSegments.OsUpdate));          // page start → second visit ends
@@ -144,7 +146,11 @@ public class TimeAttributionOsUpdateTests
         Assert.Equal(At(120, 36), update.EndUtc);
         Assert.Equal(100 * 60 + 31, update.Seconds);
         Assert.Equal(new[] { "KB5129195" }, update.Kbs);
+        Assert.Empty(update.NotInstalledKbs);
         Assert.Equal(3, update.RebootCount);
+        // downloadInstallFailureHelper and a start timeout after "restart required" are no failure:
+        // the package reached Installed after the restarts (field shape e4ecd6f8).
+        Assert.Equal(OsUpdateOutcomes.Installed, update.Outcome);
 
         // The update's restarts sit in its own segment.
         Assert.Equal(3, b.RebootSpans.Count);
@@ -363,6 +369,348 @@ public class TimeAttributionOsUpdateTests
         Assert.Equal(23 * 60, Total(b, TimeAttributionSegments.EspApps));                // the hole until the first step stays the phase's
     }
 
+    // ── the agent started after the page (v5) ───────────────────────────────
+
+    /// <summary>
+    /// Field shape 6a7d241d: the agent's first run began after the device ESP and after the page
+    /// start — it saw neither (a first run reads no Shell-Core history), only the update's later
+    /// page names and the servicing steps the watcher backfills an hour.
+    /// </summary>
+    private static List<EnrollmentEvent> LateAgentUpdate()
+    {
+        var events = new List<EnrollmentEvent>
+        {
+            Evt(T0, "agent_started", EnrollmentPhase.DeviceSetup),
+            Evt(At(2), "esp_phase_changed", EnrollmentPhase.AppsDevice),
+            // A package the OOBE itself finished during the ESP: no part of the update.
+            Servicing(At(5), "initiating", package: "KB5128942", targetState: "Staged"),
+            Servicing(At(6), "state_reached", package: "KB5128942", targetState: "Staged"),
+            Servicing(At(6, 5), "initiating", package: "KB5128942"),
+            Servicing(At(7), "state_reached", package: "KB5128942"),
+            // The update's servicing stack, staged before the agent ran.
+            Servicing(At(20), "initiating", package: "KB5124007", targetState: "Staged"),
+            Servicing(At(20, 5), "state_reached", package: "KB5124007", targetState: "Staged"),
+            // The agent runs from here on.
+            PageName(At(27, 40), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded"),
+            Servicing(At(32, 25), "initiating", package: "KB5124007"),
+            Servicing(At(33, 22), "state_reached", package: "KB5124007"),
+            Servicing(At(34), "initiating", package: "KB5129195", targetState: "Staged"),
+            Servicing(At(36), "state_reached", package: "KB5129195", targetState: "Staged"),
+            Servicing(At(36, 10), "initiating", package: "KB5054156", targetState: "Staged"),
+            Servicing(At(38), "state_reached", package: "KB5054156", targetState: "Staged"),
+            Servicing(At(38, 10), "initiating", package: "KB5129195"),
+            Servicing(At(38, 20), "initiating", package: "KB5054156"),
+            Servicing(At(43, 5), "reboot_required", package: "KB5129195"),
+            Servicing(At(43, 6), "reboot_required", package: "KB5054156"),
+            PageName(At(43, 10), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_installSucceededRebootRequired"),
+            PageName(At(43, 12), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncSucceeded"),
+            PageName(At(43, 30), "SdxWebAppCloudNDUP_rebootCountdown_starting"),
+            PageStart(At(43, 35), "RebootNDUP"),
+            RebootDetected(At(46), lastBoot: At(45)),
+            Servicing(At(50), "state_reached", package: "KB5129195"),
+            Evt(At(52), "agent_shutting_down"),
+            // The second restart; the backfilled servicing step is the first event after it.
+            Servicing(At(59, 17), "state_reached", package: "KB5054156"),
+            RebootDetected(At(59, 30), lastBoot: At(58)),
+            Evt(At(62, 10), "desktop_arrived"),
+            Evt(At(63), "enrollment_complete"),
+        };
+        return events;
+    }
+
+    [Fact]
+    public void LateAgent_UpdateBeginsAtTheFirstStepOfAPackageItAlsoServiced()
+    {
+        var b = TimeAttributionCalculator.Compute(Input(LateAgentUpdate(), At(63), 63 * 60))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        // Not the OOBE's own package at 5 min: it has no step after the update's first name.
+        Assert.Equal(At(20), update.StartUtc);
+        Assert.Equal(At(59, 17), update.EndUtc);                                         // the last step, where the second restart ends
+        Assert.Equal(39 * 60 + 17, Total(b, TimeAttributionSegments.OsUpdate));
+        Assert.Equal(2 * 60 + 53, Total(b, TimeAttributionSegments.AwaitingSignIn));     // → desktop
+        Assert.Equal(18 * 60, Total(b, TimeAttributionSegments.EspApps));
+        Assert.Equal(new[] { "KB5124007", "KB5129195", "KB5054156" }, update.Kbs);
+        Assert.Empty(update.NotInstalledKbs);
+        Assert.Equal(2, update.RebootCount);
+        Assert.Equal(OsUpdateOutcomes.Installed, update.Outcome);
+    }
+
+    [Fact]
+    public void LateAgent_WithoutItsNames_StaysTheAppsPhase()
+    {
+        // Without its names the update is invisible to a window without an observed exit (v4 saw
+        // it so even with them): the servicing steps alone never begin an update there.
+        var withoutNames = LateAgentUpdate().Where(e => e.EventType != "oobe_update_page").ToList();
+
+        var b = TimeAttributionCalculator.Compute(Input(withoutNames, At(63), 63 * 60))!;
+
+        AssertExactPartition(b);
+        Assert.Empty(b.OsUpdates);
+        Assert.Equal((62 * 60 + 10) - 2 * 60, Total(b, TimeAttributionSegments.EspApps));
+    }
+
+    [Fact]
+    public void LateAgent_NamesWithoutServicing_BeginAtTheFirstName()
+    {
+        var events = new List<EnrollmentEvent>
+        {
+            Evt(T0, "agent_started", EnrollmentPhase.DeviceSetup),
+            Evt(At(2), "esp_phase_changed", EnrollmentPhase.AppsDevice),
+            PageName(At(24), "SdxWebAppCloudNDUP_updateUSOProgressBar_DownloadPhase_progress40"),
+            PageName(At(29), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncSucceeded"),
+            PageStop(At(29, 20), "OobeNDUP", "success"),
+            Evt(At(31), "desktop_arrived"),
+            Evt(At(32), "enrollment_complete"),
+        };
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(32), 32 * 60))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(At(24), update.StartUtc);
+        Assert.Equal(At(29, 20), update.EndUtc);
+        Assert.Equal(0, update.RebootCount);
+        Assert.Equal(0, Total(b, TimeAttributionSegments.AwaitingSignIn));               // no restart: nobody was signed out
+        Assert.Equal(OsUpdateOutcomes.Installed, update.Outcome);
+        Assert.Empty(update.Kbs);
+    }
+
+    [Fact]
+    public void MissedFirstVisit_BeginsAtItsNames_NotAtTheSecondVisit()
+    {
+        // The agent missed visit 1 (it updated and restarted) and saw the confirmation visit,
+        // which holds no evidence of its own: v4 found no update at all.
+        var events = DeviceEsp();
+        events.RemoveAll(e => e.EventType == "esp_exiting");
+        events.AddRange(new[]
+        {
+            Servicing(At(21), "initiating", targetState: "Staged"),
+            PageName(At(23), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Servicing(At(30), "state_reached", targetState: "Staged"),
+            Servicing(At(30, 10), "initiating"),
+            Servicing(At(36), "reboot_required"),
+            PageName(At(36, 5), "SdxWebAppCloudNDUP_rebootCountdown_starting"),
+            PageStart(At(36, 10), "RebootNDUP"),
+            RebootDetected(At(38), lastBoot: At(37)),
+            Servicing(At(39), "state_reached"),
+            PageStart(At(39, 10), "OobeNDUP"),
+            PageStop(At(39, 30), "OobeNDUP", "success"),
+            Evt(At(41), "desktop_arrived"),
+            Evt(At(42), "enrollment_complete"),
+        });
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(42), 42 * 60))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(At(21), update.StartUtc);                                           // the package's first step, before the name
+        Assert.Equal(At(39, 30), update.EndUtc);
+        Assert.Equal(new[] { "KB5129195" }, update.Kbs);
+        Assert.Equal(1, update.RebootCount);
+        Assert.Equal(90, Total(b, TimeAttributionSegments.AwaitingSignIn));
+    }
+
+    [Fact]
+    public void EspExitAfterTheNames_DoesNotBoundTheBegin()
+    {
+        // An exit the agent saw after the update's names belongs to a later handoff; the begin
+        // comes from the packages the update serviced, as without an exit.
+        var events = LateAgentUpdate();
+        events.Add(Evt(At(44), "esp_exiting"));
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(63), 63 * 60))!;
+
+        AssertExactPartition(b);
+        Assert.Equal(At(20), Assert.Single(b.OsUpdates).StartUtc);
+    }
+
+    [Fact]
+    public void EspExitBeforeTheNames_BoundsTheBeginAsInV4()
+    {
+        // A known exit before the names: the first servicing step after it begins the update —
+        // the KB staged during the ESP stays out, whatever the update did with it later.
+        var events = LateAgentUpdate();
+        events.Add(Evt(At(25), "esp_exiting"));
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(63), 63 * 60))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(At(27, 40), update.StartUtc);                                       // no step between the exit and the first name
+        Assert.Equal(new[] { "KB5124007", "KB5129195", "KB5054156" }, update.Kbs);
+    }
+
+    [Fact]
+    public void NamesAfterTheUserIsBack_AreNoUpdate()
+    {
+        var events = WithAccountPhase(new[]
+        {
+            PageName(At(28, 30), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded"),
+            PageName(At(29), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncSucceeded"),
+        });
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(30), 1800))!;
+
+        AssertExactPartition(b);
+        Assert.Empty(b.OsUpdates);
+    }
+
+    [Fact]
+    public void WhiteGlove_PartOneExit_DoesNotBeginAnUpdateInPartTwo()
+    {
+        // v4 took the session's first exit: part 1's let a servicing step in part 2 begin an
+        // update. Part 2 here has no exit, no page and no update name — no update.
+        var part1End = At(30);
+        var resumedAt = T0.AddDays(2);
+        var completedAt = resumedAt.AddMinutes(20);
+        var events = new List<EnrollmentEvent>
+        {
+            Evt(T0, "agent_started", EnrollmentPhase.DeviceSetup),
+            Evt(At(2), "esp_phase_changed", EnrollmentPhase.AppsDevice),
+            Evt(At(25), "esp_exiting"),
+            Evt(part1End, "whiteglove_part1_complete"),
+            Evt(resumedAt.AddSeconds(30), "agent_started", EnrollmentPhase.DeviceSetup),
+            Evt(resumedAt.AddMinutes(1), "esp_phase_changed", EnrollmentPhase.AppsDevice),
+            Servicing(resumedAt.AddMinutes(5), "initiating", targetState: "Staged"),
+            Servicing(resumedAt.AddMinutes(8), "state_reached", targetState: "Staged"),
+            Evt(resumedAt.AddMinutes(15), "esp_phase_changed", EnrollmentPhase.AccountSetup),
+            Evt(resumedAt.AddMinutes(16), "hello_wizard_started"),
+            Evt(resumedAt.AddMinutes(19), "desktop_arrived"),
+            Evt(completedAt, "enrollment_complete"),
+        };
+
+        var b = TimeAttributionCalculator.Compute(
+            Input(events, completedAt, durationSeconds: 30 * 60 + 20 * 60, wg: true, resumedAt: resumedAt))!;
+
+        AssertExactPartition(b);
+        Assert.Empty(b.OsUpdates);
+    }
+
+    // ── outcome ─────────────────────────────────────────────────────────────
+
+    [Fact]
+    public void FailedDownload_IsFailed_AndTheStagedKbIsNotInstalled()
+    {
+        // Field shape e7551b82: only the servicing stack staged; the download failed after 25
+        // minutes, the page restarted the device, and the second visit found nothing to offer.
+        var events = DeviceEsp();
+        events.AddRange(new[]
+        {
+            PageStart(At(20, 2), "OobeNDUP"),
+            PageName(At(20, 3), "ExpeditedUpdate_isNDUPAllowedByCSPSucceeded", "true"),
+            PageName(At(21, 42), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            Servicing(At(22), "initiating", package: "KB5124007", targetState: "Staged"),
+            Servicing(At(26), "state_reached", package: "KB5124007", targetState: "Staged"),
+            PageName(At(45, 10), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError"),
+            PageName(At(45, 12), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure"),
+            PageName(At(45, 13), "SdxWebAppCloudNDUP_downloadInstallFailureHelper"),
+            PageStop(At(45, 20), "OobeNDUP", "fail"),
+            PageStart(At(45, 20), "RebootNDUP"),
+            RebootDetected(At(46, 30), lastBoot: At(45, 50)),
+            PageStart(At(46, 51), "OobeNDUP"),
+            PageName(At(46, 52), "SdxWebAppCloudNDUP_initialize_NDUPDownloadInstallPreviousFailureCount", "1"),
+            PageName(At(47, 10), "SdxWebAppCloudNDUP_updateManager_processUpdatesMetadata_osUpdatesWithNDUPPI", "false"),
+            PageStop(At(47, 13), "OobeNDUP", "cancel"),
+            Evt(At(48, 15), "desktop_arrived"),
+            Evt(At(50), "enrollment_complete"),
+        });
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(50), 3000))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(At(20, 2), update.StartUtc);
+        Assert.Equal(At(47, 13), update.EndUtc);
+        Assert.Equal(OsUpdateOutcomes.Failed, update.Outcome);
+        Assert.Empty(update.Kbs);
+        Assert.Equal(new[] { "KB5124007" }, update.NotInstalledKbs);
+        Assert.Equal(1, update.RebootCount);
+    }
+
+    [Fact]
+    public void FailureThenSkip_IsSkipped()
+    {
+        // Field shape cb1992b8: visit 1 failed; visit 2 downloaded again, and someone selected
+        // Skip before the install began.
+        var events = DeviceEsp();
+        events.AddRange(new[]
+        {
+            PageStart(At(20, 2), "OobeNDUP"),
+            PageName(At(21), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            PageName(At(30), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError"),
+            PageName(At(30, 2), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncFailure"),
+            PageStop(At(30, 10), "OobeNDUP", "fail"),
+            PageStart(At(30, 10), "RebootNDUP"),
+            RebootDetected(At(31, 30), lastBoot: At(30, 40)),
+            PageStart(At(32), "OobeNDUP"),
+            PageName(At(32, 1), "SdxWebAppCloudNDUP_initialize_NDUPDownloadInstallPreviousFailureCount", "1"),
+            PageName(At(33), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded"),
+            PageName(At(40), "SdxWebAppCloudNDUP_manageProgressBars_waitingForInstallStartError"),
+            PageName(At(41), "CloudNDUPSkipDownloadInstallButtonClicked", "0"),
+            PageStop(At(41, 5), "OobeNDUP", "cancel"),
+            Evt(At(43), "desktop_arrived"),
+            Evt(At(44), "enrollment_complete"),
+        });
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(44), 2640))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(OsUpdateOutcomes.Skipped, update.Outcome);
+        Assert.Equal(At(41, 5), update.EndUtc);
+    }
+
+    [Fact]
+    public void FailureRetriedAndInstalled_IsInstalled()
+    {
+        var events = DeviceEsp();
+        events.AddRange(new[]
+        {
+            PageStart(At(20, 2), "OobeNDUP"),
+            PageName(At(21), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted"),
+            PageName(At(25), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadFailedError"),
+            PageName(At(26), "SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded"),
+            Servicing(At(27), "initiating"),
+            Servicing(At(30), "state_reached"),
+            PageName(At(30, 5), "ExpeditedUpdate_commitExpeditionDownloadInstallAsyncSucceeded"),
+            PageStop(At(30, 10), "OobeNDUP", "success"),
+            Evt(At(32), "desktop_arrived"),
+            Evt(At(33), "enrollment_complete"),
+        });
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(33), 1980))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(OsUpdateOutcomes.Installed, update.Outcome);
+        Assert.Equal(new[] { "KB5129195" }, update.Kbs);
+    }
+
+    [Fact]
+    public void FailedServicingStep_IsFailed()
+    {
+        var events = DeviceEsp();
+        events.AddRange(new[]
+        {
+            PageStart(At(20, 2), "OobeNDUP"),
+            Servicing(At(22), "initiating"),
+            Servicing(At(28), "failed"),
+            PageStop(At(28, 30), "OobeNDUP", "cancel"),
+            Evt(At(30), "desktop_arrived"),
+            Evt(At(31), "enrollment_complete"),
+        });
+
+        var b = TimeAttributionCalculator.Compute(Input(events, At(31), 1860))!;
+
+        AssertExactPartition(b);
+        var update = Assert.Single(b.OsUpdates);
+        Assert.Equal(OsUpdateOutcomes.Failed, update.Outcome);
+        Assert.Empty(update.Kbs);
+        Assert.Equal(new[] { "KB5129195" }, update.NotInstalledKbs);
+    }
+
     [Theory]
     [InlineData("ExpeditedUpdate_commitExpeditionDownloadInstallAsyncStarted", true)]
     [InlineData("SdxWebAppCloudNDUP_processStatusChangeFromHandler_downloadSucceeded", true)]
@@ -448,6 +796,9 @@ public class TimeAttributionOsUpdateTests
         var update = Assert.Single(b.OsUpdates);
         Assert.Equal(At(25), update.EndUtc);                                             // the step after the failure is not attributed
         Assert.Equal(4 * 60 + 58, Total(b, TimeAttributionSegments.OsUpdate));
+        Assert.Empty(update.Kbs);                                                        // only staged before the bound
+        Assert.Equal(new[] { "KB5129195" }, update.NotInstalledKbs);
+        Assert.Equal(OsUpdateOutcomes.Unknown, update.Outcome);
         Assert.Equal(0, Total(b, TimeAttributionSegments.AwaitingSignIn));
         Assert.True(b.UnattributedSeconds >= 10 * 60);                                   // the post-failure tail stays unattributed
     }

src/Backend/AutopilotMonitor.Functions.Tests/TimeAttributionPersistenceAndAggregationTests.cs

@@ -53,7 +53,12 @@ public class TimeAttributionPersistenceAndAggregationTests
             },
             OsUpdates = new List<OsUpdateSpan>
             {
-                new() { StartUtc = T0.AddMinutes(9), EndUtc = T0.AddMinutes(19), Seconds = 600, Kbs = new List<string> { "KB5129195", "KB5054156" }, RebootCount = 2 },
+                new()
+                {
+                    StartUtc = T0.AddMinutes(9), EndUtc = T0.AddMinutes(19), Seconds = 600,
+                    Kbs = new List<string> { "KB5129195", "KB5054156" }, NotInstalledKbs = new List<string> { "KB5124007" },
+                    Outcome = OsUpdateOutcomes.Failed, RebootCount = 2,
+                },
             },
             BlockingApps = new List<BlockingAppInterval>
             {
@@ -98,6 +103,8 @@ public class TimeAttributionPersistenceAndAggregationTests
         Assert.Equal(T0.AddMinutes(19), update.EndUtc);
         Assert.Equal(600, update.Seconds);
         Assert.Equal(new[] { "KB5129195", "KB5054156" }, update.Kbs);
+        Assert.Equal(new[] { "KB5124007" }, update.NotInstalledKbs);
+        Assert.Equal(OsUpdateOutcomes.Failed, update.Outcome);
         Assert.Equal(2, update.RebootCount);
 
         var app = Assert.Single(mapped.BlockingApps);
@@ -117,6 +124,21 @@ public class TimeAttributionPersistenceAndAggregationTests
         Assert.Empty(TableStorageService.MapToSessionTimeBreakdown(entity).OsUpdates);
     }
 
+    [Fact]
+    public void BreakdownEntity_OsUpdateWrittenBeforeTheOutcome_MapsToUnknown()
+    {
+        // v4 spans carry no Outcome/NotInstalledKbs until the sweep recomputes them.
+        var entity = TableStorageService.BuildSessionTimeBreakdownEntity(
+            new SessionTimeBreakdown { TenantId = TenantA, SessionId = "s-1", WallClockSeconds = 600 });
+        entity["OsUpdatesJson"] =
+            "[{\"StartUtc\":\"2026-10-02T14:00:00Z\",\"EndUtc\":\"2026-10-02T14:10:00Z\",\"Seconds\":600,\"Kbs\":[\"KB5129195\"],\"RebootCount\":1}]";
+
+        var update = Assert.Single(TableStorageService.MapToSessionTimeBreakdown(entity).OsUpdates);
+        Assert.Equal(OsUpdateOutcomes.Unknown, update.Outcome);
+        Assert.Empty(update.NotInstalledKbs);
+        Assert.Equal(new[] { "KB5129195" }, update.Kbs);
+    }
+
     [Fact]
     public void BreakdownEntity_OccupancyTriState_AbsentColumnMapsToNull_NeverZero()
     {

src/Backend/AutopilotMonitor.Functions/Helpers/TimeAttributionCalculator.cs

@@ -67,10 +67,11 @@ public sealed class TimeAttributionInput
 /// <c>system_reboot_detected</c> event is detection-time-stamped by the next run and never used
 /// as the reboot moment (audit Q7). Reboots are a cross-cutting annotation, not a segment.</item>
 /// <item><b>The OOBE quality update takes its time from the phase segments</b> (v4, D-314):
-/// <c>os_update</c> from the start of the update page that installed an update to the last
-/// update evidence before the user is back, then — after a restart — <c>awaiting_sign_in</c>
-/// until the first evidence of the user. Without update evidence (the page cancelled or found
-/// nothing) the partition is the phase partition unchanged.</item>
+/// <c>os_update</c> from the start of the update page that worked on an update — or, when the
+/// agent started after the page, from the update's first evidence (v5) — to the last update
+/// evidence before the user is back, then — after a restart — <c>awaiting_sign_in</c> until the
+/// first evidence of the user. Without update evidence (the page cancelled or found nothing) the
+/// partition is the phase partition unchanged. The latest outcome evidence names the outcome.</item>
 /// </list>
 /// </summary>
 public static class TimeAttributionCalculator
@@ -82,7 +83,9 @@ public static class TimeAttributionCalculator
     // annotations mirroring RebootSpans; the maintenance sweep recomputes older rows.
     // v4: os_update + awaiting_sign_in — the OOBE quality update and the wait for the user after
     // its restart, cut out of the phase segment they overlap (D-314), with OsUpdates naming the KBs.
-    public const int CurrentVersion = 4;
+    // v5: an update whose page start the agent missed begins at its first evidence; the device-ESP
+    // exit is the window's own; OsUpdates carry the outcome and split installed from not installed KBs.
+    public const int CurrentVersion = 5;
 
     /// <summary>
     /// Enrollment class for fleet aggregation — classes are NEVER mixed in one aggregate (a
@@ -217,6 +220,8 @@ public static class TimeAttributionCalculator
                     EndUtc = u.End,
                     Seconds = ClampToWindows(u.Start, u.End, windows)?.Seconds ?? 0,
                     Kbs = u.Kbs,
+                    NotInstalledKbs = u.NotInstalledKbs,
+                    Outcome = u.Outcome,
                     RebootCount = u.RebootCount,
                 })
                 .ToList(),
@@ -774,28 +779,55 @@ public static class TimeAttributionCalculator
         public DateTime? AwaitingSignInEnd;
 
         public List<string> Kbs = new();
+        public List<string> NotInstalledKbs = new();
+        public string Outcome = OsUpdateOutcomes.Unknown;
         public int RebootCount;
     }
 
     private readonly struct PageRecord
     {
-        public PageRecord(DateTime at, string cxhEvent, string? page, string? name)
+        public PageRecord(DateTime at, string cxhEvent, string? page, string? name, string? result)
         {
             At = at;
             CxhEvent = cxhEvent;
             Page = page;
             Name = name;
+            Result = result;
         }
 
         public DateTime At { get; }
         public string CxhEvent { get; }
         public string? Page { get; }
         public string? Name { get; }
+        public string? Result { get; }
 
         public bool IsStartOf(string page) => CxhEvent == "page_started" && string.Equals(Page, page, StringComparison.OrdinalIgnoreCase);
         public bool IsStopOf(string page) => CxhEvent == "page_stopped" && string.Equals(Page, page, StringComparison.OrdinalIgnoreCase);
     }
 
+    /// <summary>One CBS servicing step (<c>windows_update_servicing</c>) of an OS package.</summary>
+    private readonly struct ServicingStep
+    {
+        public ServicingStep(DateTime at, string? package, string? step, string? targetState)
+        {
+            At = at;
+            Package = package;
+            Step = step;
+            TargetState = targetState;
+        }
+
+        public DateTime At { get; }
+        public string? Package { get; }
+        public string? Step { get; }
+        public string? TargetState { get; }
+
+        public bool ReachedInstalled =>
+            string.Equals(Step, "state_reached", StringComparison.OrdinalIgnoreCase) &&
+            string.Equals(TargetState, "Installed", StringComparison.OrdinalIgnoreCase);
+
+        public bool Failed => string.Equals(Step, "failed", StringComparison.OrdinalIgnoreCase);
+    }
+
     /// <summary>
     /// Page names that only an update in progress writes (field data 2026-10-02). Every visit
     /// logs init names such as <c>initialize_NDUPInstallCanceledInOptOut</c> and
@@ -818,21 +850,48 @@ public static class TimeAttributionCalculator
     /// The update page's own record of a download or an install — evidence of an update next to
     /// the servicing steps (an agent caps the page names per run, so this is the weaker of the two).
     /// </summary>
-    internal static bool IsUpdateActivityName(string? name) =>
+    internal static bool IsUpdateActivityName(string? name) => HasMarker(name, UpdateActivityMarkers);
+
+    // Outcome evidence on the update page (field data 2026-10-03/05). Only the explicit failures
+    // count: an update that installed fine can still log downloadInstallFailureHelper and a start
+    // timeout after its "restart required" (session shape e4ecd6f8).
+    private static readonly string[] UpdateSucceededMarkers =
+    {
+        "installSucceededRebootRequired",               // also the _lcu twin
+        "commitExpeditionDownloadInstallAsyncSucceeded",
+    };
+
+    private static readonly string[] UpdateFailedMarkers =
+    {
+        "downloadFailedError",
+        "installFailedError",
+        "commitExpeditionDownloadInstallAsyncFailure",
+    };
+
+    private static readonly string[] UpdateSkippedMarkers =
+    {
+        "SkipDownloadInstallButtonClicked",             // someone selected Skip on the page
+    };
+
+    private static bool HasMarker(string? name, string[] markers) =>
         name != null &&
-        UpdateActivityMarkers.Any(marker => name.IndexOf(marker, StringComparison.OrdinalIgnoreCase) >= 0);
+        markers.Any(marker => name.IndexOf(marker, StringComparison.OrdinalIgnoreCase) >= 0);
 
     /// <summary>
-    /// At most one update per observation window. <b>Begin:</b> the start of the update page
-    /// (<see cref="UpdatePage"/>) whose visit holds update evidence — a servicing step or an
+    /// At most one update per observation window. <b>Begin:</b> update-activity names the agent
+    /// saw before the first observed start of the update page (<see cref="UpdatePage"/>) — it
+    /// started after the visit they belong to — begin at the earliest of the first such name and
+    /// the update's first servicing step (see <see cref="FindUpdateBegin"/>). Otherwise the start
+    /// of the update page whose visit holds update evidence — a servicing step or an
     /// update-activity name before the visit ends (its stop, the <see cref="UpdateRestartPage"/>
-    /// start or the next visit). Only when no page start was observed in the window: the first
-    /// servicing step after the device-ESP exit. Never after the user is back. <b>Bound:</b> the first evidence of the
-    /// user (user ESP apps, desktop, Hello wizard, a Complete declaration), the end of
-    /// attribution (Failed) or the window end. <b>End:</b> the latest update evidence before the
-    /// bound — page record, servicing step, or the end of a restart that began in the interval.
-    /// With a restart in the interval the user is signed out: <c>awaiting_sign_in</c> runs from
-    /// the end to the bound.
+    /// start or the next visit). Only when no page start and no such name was observed in the
+    /// window: the first servicing step after the window's device-ESP exit. Never after the user
+    /// is back. <b>Bound:</b> the first evidence of the user (user ESP apps, desktop, Hello
+    /// wizard, a Complete declaration), the end of attribution (Failed) or the window end.
+    /// <b>End:</b> the latest update evidence before the bound — page record, servicing step, or
+    /// the end of a restart that began in the interval. With a restart in the interval the user
+    /// is signed out: <c>awaiting_sign_in</c> runs from the end to the bound. <b>Outcome:</b> the
+    /// latest outcome evidence in [begin, bound) — see <see cref="ResolveOutcome"/>.
     /// </summary>
     private static List<OsUpdate> BuildOsUpdates(
         List<EnrollmentEvent> events, List<Window> windows, List<Anchor> anchors,
@@ -841,7 +900,7 @@ public static class TimeAttributionCalculator
         var result = new List<OsUpdate>();
 
         var pages = new List<PageRecord>();
-        var servicing = new List<(DateTime At, string? Package)>();
+        var servicing = new List<ServicingStep>();
         foreach (var evt in events)
         {
             if (evt.EventType == Constants.EventTypes.OobeUpdatePage && evt.Data != null)
@@ -849,11 +908,14 @@ public static class TimeAttributionCalculator
                 pages.Add(new PageRecord(evt.Timestamp,
                     DataString(evt.Data, "cxhEvent") ?? string.Empty,
                     DataString(evt.Data, "page"),
-                    DataString(evt.Data, "name")));
+                    DataString(evt.Data, "name"),
+                    DataString(evt.Data, "result")));
             }
             else if (evt.EventType == Constants.EventTypes.WindowsUpdateServicing)
             {
-                servicing.Add((evt.Timestamp, evt.Data != null ? DataString(evt.Data, "package") : null));
+                servicing.Add(evt.Data != null
+                    ? new ServicingStep(evt.Timestamp, DataString(evt.Data, "package"), DataString(evt.Data, "step"), DataString(evt.Data, "targetState"))
+                    : new ServicingStep(evt.Timestamp, null, null, null));
             }
         }
         if (servicing.Count == 0 && !pages.Any(p => IsUpdateActivityName(p.Name))) return result;
@@ -874,11 +936,17 @@ public static class TimeAttributionCalculator
             .OrderBy(t => t)
             .ToList();
         var attributionEnd = anchors.FirstOrDefault(a => a.Bucket == null)?.Ts;
-        var deviceEspExit = events.FirstOrDefault(e => e.EventType == Constants.EventTypes.EspExiting)?.Timestamp;
+        // esp_exiting fires for the Device→Account handoff AND the final exit and is never
+        // replayed; each window picks its own (a WhiteGlove part-1 exit never bounds part 2).
+        var espExits = events
+            .Where(e => e.EventType == Constants.EventTypes.EspExiting)
+            .Select(e => e.Timestamp)
+            .OrderBy(t => t)
+            .ToList();
 
         foreach (var window in windows)
         {
-            var begin = FindUpdateBegin(window, pages, evidence, servicing, deviceEspExit, userBack);
+            var begin = FindUpdateBegin(window, pages, evidence, servicing, espExits, userBack, attributionEnd);
             if (!begin.HasValue) continue;
 
             var bound = window.End;
@@ -896,13 +964,22 @@ public static class TimeAttributionCalculator
             {
                 if (page.At > update.End && page.At < bound) update.End = page.At;
             }
-            foreach (var (at, package) in servicing)
+            var servicedKbs = new List<string>();
+            var installedKbs = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+            foreach (var step in servicing)
             {
-                if (at < begin.Value || at >= bound) continue;
-                if (at > update.End) update.End = at;
-                var kb = ExtractKb(package);
-                if (kb != null && !update.Kbs.Contains(kb)) update.Kbs.Add(kb);
+                if (step.At < begin.Value || step.At >= bound) continue;
+                if (step.At > update.End) update.End = step.At;
+                var kb = ExtractKb(step.Package);
+                if (kb == null) continue;
+                if (!servicedKbs.Contains(kb)) servicedKbs.Add(kb);
+                if (step.ReachedInstalled) installedKbs.Add(kb);
             }
+            // A KB counts as installed only once its package reached "Installed"; a failed
+            // update can leave packages staged.
+            update.Kbs = servicedKbs.Where(installedKbs.Contains).ToList();
+            update.NotInstalledKbs = servicedKbs.Where(kb => !installedKbs.Contains(kb)).ToList();
+            update.Outcome = ResolveOutcome(pages, servicing, begin.Value, bound);
             foreach (var (gapStart, gapEnd) in rebootGaps)
             {
                 if (gapStart < begin.Value || gapStart >= bound) continue;
@@ -923,11 +1000,86 @@ public static class TimeAttributionCalculator
     }
 
     private static DateTime? FindUpdateBegin(
-        Window window, List<PageRecord> pages, List<DateTime> evidence,
-        List<(DateTime At, string? Package)> servicing, DateTime? deviceEspExit, List<DateTime> userBack)
+        Window window, List<PageRecord> pages, List<DateTime> evidence, List<ServicingStep> servicing,
+        List<DateTime> espExits, List<DateTime> userBack, DateTime? attributionEnd)
     {
         // An update after the user is back runs beside the enrollment, not instead of it.
         bool UserBackBy(DateTime t) => userBack.Any(u => u > window.Start && u <= t);
+        bool InWindow(DateTime t) => t >= window.Start && t < window.End;
+
+        // This window's device-ESP exit before the given moment, if one was observed.
+        DateTime? EspExitBefore(DateTime before)
+        {
+            foreach (var exit in espExits)
+            {
+                if (exit < window.Start) continue;
+                if (exit >= window.End || exit >= before) break;
+                return exit;
+            }
+            return null;
+        }
+
+        DateTime? firstPageStart = null;
+        foreach (var page in pages)
+        {
+            if (!page.IsStartOf(UpdatePage) || !InWindow(page.At)) continue;
+            firstPageStart = page.At;
+            break;
+        }
+
+        // Update-activity names before the first observed page start: the agent started after
+        // the visit they belong to (a first run reads no Shell-Core history), so its start is
+        // missing. Evaluated first — their visit lies before any observed one.
+        DateTime? firstOrphanName = null;
+        foreach (var page in pages)
+        {
+            if (firstPageStart.HasValue && page.At >= firstPageStart.Value) break;
+            if (!InWindow(page.At) || !IsUpdateActivityName(page.Name) || UserBackBy(page.At)) continue;
+            firstOrphanName = page.At;
+            break;
+        }
+        if (firstOrphanName.HasValue)
+        {
+            var firstName = firstOrphanName.Value;
+            DateTime? firstStep = null;
+            var exitBefore = EspExitBefore(firstName);
+            if (exitBefore.HasValue)
+            {
+                // A known exit bounds it as in v4: the first servicing step after the exit.
+                foreach (var step in servicing)
+                {
+                    if (step.At < exitBefore.Value || step.At < window.Start) continue;
+                    if (step.At < firstName) firstStep = step.At;
+                    break;
+                }
+            }
+            else
+            {
+                // No exit observed: the earliest step of a package this update also serviced at or
+                // after its first name — the servicing watcher backfills an hour, so the update's
+                // early staging is there; a package finished before (the OOBE's own) is not.
+                var limit = window.End;
+                if (attributionEnd.HasValue && attributionEnd.Value < limit) limit = attributionEnd.Value;
+                foreach (var u in userBack)
+                {
+                    if (u <= firstName) continue;
+                    if (u < limit) limit = u;
+                    break;
+                }
+                var members = new HashSet<string>(
+                    servicing.Where(s => s.At >= firstName && s.At < limit && !string.IsNullOrEmpty(s.Package)).Select(s => s.Package!),
+                    StringComparer.OrdinalIgnoreCase);
+                foreach (var step in servicing)
+                {
+                    if (step.At < window.Start) continue;
+                    if (step.At >= firstName) break;
+                    if (string.IsNullOrEmpty(step.Package) || !members.Contains(step.Package!)) continue;
+                    firstStep = step.At;
+                    break;
+                }
+            }
+            return firstStep.HasValue && firstStep.Value < firstName ? firstStep.Value : firstName;
+        }
 
         var pageStartSeen = false;
         for (var i = 0; i < pages.Count; i++)
@@ -963,17 +1115,62 @@ public static class TimeAttributionCalculator
         // a servicing step beside it is some other update.
         if (pageStartSeen) return null;
 
-        // Fallback: the page start was not observed (the agent started after it). The first
-        // servicing step after the device-ESP exit — without the download before it.
-        if (!deviceEspExit.HasValue) return null;
-        foreach (var (at, _) in servicing)
+        // Fallback: neither the page start nor an update name was observed (the agent started
+        // after the page and saw only CBS). The first servicing step after this window's
+        // device-ESP exit before the user is back — without the download before it.
+        DateTime? deviceEspExit = null;
+        foreach (var exit in espExits)
         {
-            if (at < deviceEspExit.Value || at < window.Start || at >= window.End) continue;
-            return UserBackBy(at) ? null : at;
+            if (exit < window.Start) continue;
+            if (exit >= window.End || UserBackBy(exit)) break;
+            deviceEspExit = exit;
+            break;
+        }
+        if (!deviceEspExit.HasValue) return null;
+        foreach (var step in servicing)
+        {
+            if (step.At < deviceEspExit.Value || step.At < window.Start || step.At >= window.End) continue;
+            return UserBackBy(step.At) ? null : step.At;
         }
         return null;
     }
 
+    /// <summary>
+    /// How the update in [begin, bound) ended: the latest outcome evidence decides — a package
+    /// reaching "Installed" or the page's install success (installed), an explicit download or
+    /// install failure, a failed servicing step or a page stop with result "fail" (failed), or the
+    /// page's Skip button (skipped). A later attempt overrides an earlier one (a failure retried
+    /// and installed is installed; a failure followed by Skip is skipped). No evidence: unknown.
+    /// </summary>
+    private static string ResolveOutcome(List<PageRecord> pages, List<ServicingStep> servicing, DateTime begin, DateTime bound)
+    {
+        DateTime? latest = null;
+        var outcome = OsUpdateOutcomes.Unknown;
+        void Consider(DateTime at, string kind)
+        {
+            if (latest.HasValue && at < latest.Value) return;
+            latest = at;
+            outcome = kind;
+        }
+
+        foreach (var page in pages)
+        {
+            if (page.At < begin || page.At >= bound) continue;
+            if (HasMarker(page.Name, UpdateSucceededMarkers)) Consider(page.At, OsUpdateOutcomes.Installed);
+            else if (HasMarker(page.Name, UpdateFailedMarkers)) Consider(page.At, OsUpdateOutcomes.Failed);
+            else if (HasMarker(page.Name, UpdateSkippedMarkers)) Consider(page.At, OsUpdateOutcomes.Skipped);
+            else if (page.IsStopOf(UpdatePage) && string.Equals(page.Result, "fail", StringComparison.OrdinalIgnoreCase))
+                Consider(page.At, OsUpdateOutcomes.Failed);
+        }
+        foreach (var step in servicing)
+        {
+            if (step.At < begin || step.At >= bound) continue;
+            if (step.ReachedInstalled) Consider(step.At, OsUpdateOutcomes.Installed);
+            else if (step.Failed) Consider(step.At, OsUpdateOutcomes.Failed);
+        }
+        return outcome;
+    }
+
     private static string? ExtractKb(string? package)
     {
         if (string.IsNullOrEmpty(package)) return null;

src/Backend/AutopilotMonitor.Functions/Services/EventIngestProcessor.Classification.cs

@@ -1,4 +1,5 @@
 using AutopilotMonitor.DecisionCore.State;
+using AutopilotMonitor.Shared;
 using AutopilotMonitor.Shared.Models;
 using Microsoft.Extensions.Logging;
 
@@ -9,19 +10,18 @@ namespace AutopilotMonitor.Functions.Services
     /// </summary>
     public sealed partial class EventIngestProcessor
     {
-        private EventClassification ClassifyEvents(List<EnrollmentEvent> storedEvents)
+        internal static EventClassification ClassifyEvents(List<EnrollmentEvent> storedEvents)
         {
             var classification = new EventClassification();
 
             foreach (var evt in storedEvents)
             {
-                // System-timeline-watcher rows (clock steps, sleep episodes) are backfilled
-                // from the Windows event log with original timestamps up to 24h before the
-                // agent started — environment observation, not enrollment activity. They must
-                // not pull the session anchor toward pre-enrollment OOBE idle time (mirrors
-                // TableStorageService.IsSessionAnchorEligible on the Events-table probe;
-                // field case d0c5b672).
-                var anchorEligible = evt.Source != "SystemTimelineWatcher";
+                // Backfilled environment observations (clock steps, sleep, update and servicing
+                // activity from before the agent started) are timeline rows, not enrollment
+                // activity: they must not pull the session anchor into pre-enrollment time
+                // (Constants.EventSources.SessionAnchorIneligible; the Events-table probe applies
+                // the same rule).
+                var anchorEligible = Constants.EventSources.IsSessionAnchorEligible(evt.Source);
                 if (anchorEligible &&
                     (!classification.EarliestEventTimestamp.HasValue || evt.Timestamp < classification.EarliestEventTimestamp.Value))
                     classification.EarliestEventTimestamp = evt.Timestamp;
@@ -480,6 +480,9 @@ namespace AutopilotMonitor.Functions.Services
             // observation too — a device that slept through its stall must stay Stalled.
             "system_clock_changed" => true,
             "system_sleep_episode" => true,
+            // A platform run corrected after the fact from IME's saved result (D-316): registry
+            // observation of an earlier run, not progress — a stalled session stays Stalled.
+            Constants.EventTypes.ScriptOutputReconciliation => true,
             _ => false
         };
 

src/Backend/AutopilotMonitor.Functions/Services/MaintenanceService.Aggregation.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Text;
@@ -795,7 +796,7 @@ namespace AutopilotMonitor.Functions.Services
 
                 var containerClient = new BlobContainerClient(new Uri(containerSasUrl));
                 var generatedAtUtc = DateTime.UtcNow;
-                var versionedFileName = $"platform-stats.{generatedAtUtc:yyyy-MM-dd}.json";
+                var versionedFileName = PlatformStatsVersionedFileName(generatedAtUtc);
 
                 var versionedPayload = new
                 {
@@ -831,19 +832,34 @@ namespace AutopilotMonitor.Functions.Services
             }
         }
 
+        /// <summary>
+        /// Name of the versioned stats file of one publish. The file is served immutable for a year
+        /// (<see cref="PlatformStatsVersionedCacheControl"/>), so a name must never be written twice:
+        /// maintenance publishes every 2 hours, and the per-day name of the once-a-night schedule was
+        /// rewritten up to 12 times a day under that header — caches kept the first copy of the day.
+        /// Browsers revalidate only the manifest, which names the current file.
+        /// </summary>
+        internal static string PlatformStatsVersionedFileName(DateTime generatedAtUtc) =>
+            $"platform-stats.{generatedAtUtc.ToString("yyyy-MM-dd'T'HHmmss'Z'", CultureInfo.InvariantCulture)}.json";
+
         private async Task UploadJsonBlobAsync(BlobContainerClient containerClient, string blobName, object payload, string cacheControl)
         {
             var blobClient = containerClient.GetBlobClient(blobName);
             var json = JsonConvert.SerializeObject(payload);
             await using var stream = new MemoryStream(Encoding.UTF8.GetBytes(json));
 
-            await blobClient.UploadAsync(stream, overwrite: true);
-            await blobClient.SetHttpHeadersAsync(new BlobHttpHeaders
+            // Headers and tier travel with the upload, which still overwrites (the manifest relies on
+            // it). Set in follow-up calls, the blob was briefly served without Cache-Control and
+            // content type, and stayed that way when a follow-up call failed.
+            await blobClient.UploadAsync(stream, new BlobUploadOptions
             {
-                ContentType = "application/json; charset=utf-8",
-                CacheControl = cacheControl
+                HttpHeaders = new BlobHttpHeaders
+                {
+                    ContentType = "application/json; charset=utf-8",
+                    CacheControl = cacheControl
+                },
+                AccessTier = AccessTier.Hot
             });
-            await blobClient.SetAccessTierAsync(AccessTier.Hot);
         }
 
         /// <summary>

src/Backend/AutopilotMonitor.Functions/Services/MaintenanceService.cs

@@ -60,6 +60,7 @@ namespace AutopilotMonitor.Functions.Services
 
         private const string PlatformStatsAliasFileName = "platform-stats.json";
         private const string PlatformStatsAliasCacheControl = "public, max-age=300, stale-while-revalidate=86400";
+        // Holds only because every publish writes a new name (PlatformStatsVersionedFileName).
         private const string PlatformStatsVersionedCacheControl = "public, max-age=31536000, immutable";
 
         public MaintenanceService(

src/Backend/AutopilotMonitor.Functions/Services/TableStorageService.Sessions.cs

@@ -3540,18 +3540,15 @@ namespace AutopilotMonitor.Functions.Services
         }
 
         /// <summary>
-        /// Event sources whose rows never anchor the session. The system timeline watcher
-        /// backfills environment observations (clock steps, sleep episodes) from the Windows
-        /// event log with their ORIGINAL timestamps — up to 24h before the agent started.
-        /// They belong on the timeline, but they are not enrollment activity: anchoring on
-        /// them silently stretches StartedAt/DurationSeconds toward pre-enrollment OOBE idle
-        /// time (field case d0c5b672: a pre-agent clock correction pulled StartedAt ~14min
-        /// before the first real activity; the 2h backward-shift guard only caps, not
-        /// prevents, this). User decision 2026-08-21: the session anchor stays on real
-        /// enrollment activity.
+        /// Whether an event row may anchor the session (<see cref="Constants.EventSources.SessionAnchorIneligible"/>).
+        /// Backfilled environment observations carry their ORIGINAL event time, up to 24h before
+        /// the agent started; anchoring on them silently stretches StartedAt/DurationSeconds into
+        /// pre-enrollment time (field case d0c5b672: a pre-agent clock correction, ~14 min; the 2h
+        /// backward-shift guard only caps this). User decision 2026-08-21: the session anchor
+        /// stays on real enrollment activity.
         /// </summary>
         internal static bool IsSessionAnchorEligible(TableEntity eventRow)
-            => eventRow.GetString("Source") != "SystemTimelineWatcher";
+            => Constants.EventSources.IsSessionAnchorEligible(eventRow.GetString("Source"));
 
         /// <summary>
         /// Returns the earliest ANCHOR-ELIGIBLE event timestamp persisted for a session, if

src/McpServer/autopilot-monitor-mcp/src/__tests__/script-output-correction.test.ts

@@ -0,0 +1,95 @@
+/**
+ * D-316: a platform run whose script_failed came from another script's end block is corrected by a later
+ * script_output_reconciliation (outcome "foreign", IME result Success). get_session_summary must not count the
+ * stored script_failed as an error, must not rank it as one and must not attach the foreign exit code's catalog
+ * text; the correction itself stays a Warning key event.
+ *
+ * Pure unit tests: fetch is stubbed and the registered tool handler is invoked directly.
+ */
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { McpServer } from '@modelcontextprotocol/server';
+import { registerTools } from '../tools.js';
+import { runWithCaller } from '../client.js';
+import { foreignSuccessRunIds, isCorrectedForeignFailure } from '../tools/shared.js';
+
+type ToolHandler = (args: Record<string, unknown>, extra: unknown) => Promise<{ content?: Array<{ type: string; text?: string }> }>;
+
+const SESSION = 'e259c121-1234-4abc-9def-0123456789ab';
+const GA = { token: 'ga', isGlobalAdmin: true };
+const extra = { signal: new AbortController().signal };
+
+function summaryHandler(): ToolHandler {
+  const server = new McpServer({ name: 'test', version: '0.0.0' });
+  registerTools(server, undefined, undefined, undefined, true, true, false);
+  const registry = (server as unknown as { _registeredTools: Record<string, { handler: ToolHandler }> })._registeredTools;
+  return registry['get_session_summary'].handler;
+}
+
+function stubBackend(events: unknown[]): void {
+  const body = {
+    success: true,
+    session: { sessionId: SESSION, tenantId: 't', status: 'Succeeded', startedAt: '2026-10-03T20:49:00Z' },
+    events,
+    results: [],
+    annotations: [],
+    count: events.length,
+  };
+  vi.stubGlobal('fetch', vi.fn(async () => ({ ok: true, status: 200, json: async () => body, text: async () => JSON.stringify(body) }) as unknown as Response));
+}
+
+afterEach(() => vi.unstubAllGlobals());
+
+const foreignFailure = {
+  timestamp: '2026-10-03T20:59:04Z',
+  eventType: 'script_failed',
+  severity: 'Error',
+  source: 'ImeLogTracker',
+  message: 'Platform script d94468af: Success (exit: 1)',
+  data: { scriptType: 'platform', result: 'Success', exitCode: '1', runId: 'run-1' },
+};
+
+const correction = (data: Record<string, unknown>) => ({
+  timestamp: '2026-10-03T20:59:08Z',
+  eventType: 'script_output_reconciliation',
+  severity: 'Warning',
+  source: 'RegistryScriptResult',
+  message: "Platform script d94468af: output corrected from IME's saved result",
+  data: { scriptType: 'platform', outcome: 'foreign', result: 'Success', runId: 'run-1', ...data },
+});
+
+async function summary(events: unknown[]): Promise<Record<string, any>> {
+  stubBackend(events);
+  const result = await runWithCaller(GA, () => summaryHandler()({ sessionId: SESSION }, extra));
+  return JSON.parse((result.content ?? []).map((c) => c.text ?? '').join(''));
+}
+
+describe('get_session_summary with a corrected platform run', () => {
+  it('does not count the foreign script_failed as an error and drops its exit-code text', async () => {
+    const body = await summary([foreignFailure, correction({})]);
+
+    expect(body.stats.errorCount).toBe(0);
+    expect(body.stats.warningCount).toBe(1);
+    const failed = body.keyEvents.find((e: { eventType: string }) => e.eventType === 'script_failed');
+    expect(failed.correctedByImeSavedResult).toBe(true);
+    expect(failed.errorCode).toBeUndefined();
+    expect(body.keyEvents.some((e: { eventType: string }) => e.eventType === 'script_output_reconciliation')).toBe(true);
+  });
+
+  it('keeps counting a failure IME itself reported, and an uncorrected one', async () => {
+    expect((await summary([foreignFailure, correction({ result: 'Failed' })])).stats.errorCount).toBe(1);
+    expect((await summary([foreignFailure, correction({ outcome: 'repaired' })])).stats.errorCount).toBe(1);
+    expect((await summary([foreignFailure, correction({ runId: 'another-run' })])).stats.errorCount).toBe(1);
+    expect((await summary([foreignFailure])).stats.errorCount).toBe(1);
+  });
+});
+
+describe('foreignSuccessRunIds / isCorrectedForeignFailure', () => {
+  it('names only foreign corrections whose IME result is Success, and only script_failed rows', () => {
+    const runs = foreignSuccessRunIds([correction({}), correction({ runId: 'r2', result: 'Failed' }), correction({ runId: 'r3', outcome: 'repaired' })]);
+    expect([...runs]).toEqual(['run-1']);
+    expect(isCorrectedForeignFailure('script_failed', { runId: 'run-1' }, runs)).toBe(true);
+    expect(isCorrectedForeignFailure('script_completed', { runId: 'run-1' }, runs)).toBe(false);
+    expect(isCorrectedForeignFailure('script_failed', { runId: 'r2' }, runs)).toBe(false);
+    expect(isCorrectedForeignFailure('script_failed', undefined, runs)).toBe(false);
+  });
+});

src/McpServer/autopilot-monitor-mcp/src/generated/wire-types.generated.ts

@@ -3060,8 +3060,12 @@ export interface OsUpdateSpan {
   endUtc: string;
   /** In-window seconds of the interval. */
   seconds: number;
-  /** KB numbers of the packages Windows serviced in the interval ("KB5129195"), in order of first appearance; empty when no package named one. */
+  /** KB numbers of the packages that reached "Installed" in the interval ("KB5129195"), in order of first appearance; empty when none did or no package named one. */
   kbs: string[];
+  /** KB numbers of the packages Windows serviced in the interval without reaching "Installed" (for example only staged before a failed download). */
+  notInstalledKbs: string[];
+  /** How the update ended — one of OsUpdateOutcomes; the latest outcome evidence in the interval decides. */
+  outcome: string;
   /** Restarts that began inside the interval. */
   rebootCount: number;
 }

src/McpServer/autopilot-monitor-mcp/src/resource-catalog.ts

@@ -96,7 +96,7 @@ export const EVENT_TYPES_CATALOG = {
     'office_install_failed',
     'office_preinstalled_detected',
   ],
-  script_events: ['script_started', 'script_completed', 'script_failed', 'script_timeout_suspected', 'script_recurrence_summary', 'historic_ime_replay_detected'],
+  script_events: ['script_started', 'script_completed', 'script_failed', 'script_output_reconciliation', 'script_timeout_suspected', 'script_recurrence_summary', 'historic_ime_replay_detected'],
   network_events: [
     'network_state_change',
     'network_connectivity_check',

src/McpServer/autopilot-monitor-mcp/src/tools/admin.ts

@@ -2060,8 +2060,8 @@ export function registerAdminTools(server: McpServer, ga: boolean, strictGa: boo
         'time breakdown — wall-clock partition into device_prep / esp_apps / os_update / awaiting_sign_in / ' +
         'identity_hello / user_esp / desktop_handoff spans plus an EXPLICIT unattributed remainder (sums are exact ' +
         'against the session\'s authoritative duration; the WhiteGlove pause is excluded by design; os_update = the ' +
-        'OOBE quality update, its KBs and restarts in osUpdates; awaiting_sign_in = after that update\'s restart ' +
-        'until the user is back), the ESP-blocking app install ' +
+        'OOBE quality update, its outcome, installed and not installed KBs and restarts in osUpdates; ' +
+        'awaiting_sign_in = after that update\'s restart until the user is back), the ESP-blocking app install ' +
         'intervals with critical-path occupancy (an app\'s seconds = its ACTIVE install time summed across all ' +
         'IME passes/attempts — deliberately broader than get_app_install_metrics\' final-attempt duration, ' +
         'because a failed attempt and an evaluation pass still occupied the critical path), reboot outage ' +

src/McpServer/autopilot-monitor-mcp/src/tools/sessions.ts

@@ -2,7 +2,7 @@ import { McpServer } from '@modelcontextprotocol/server';
 import { z } from 'zod';
 import { ApiError, apiFetch, buildQuery, jsonBody, DEFAULT_FIRST_PAGE_SIZE, effectivePageSize, enforceDelegatedTenant, enforceDelegatedTenantForPage, followNextLink, pageSizeForCall, pickGlobalOrTenantPath, scanUntilMatch, scanWithTimeoutFallback } from '../client.js';
 import { withToolTelemetry } from '../telemetry.js';
-import { READ_ONLY, MAX_RESULT_SIZE_CHARS, LEAN_EVENT_FIELDS, LEAN_EVENT_OMISSION, leanFieldSelection, SUMMARY_EVENT_FIELDS, toolResultText, SessionIdSchema, isBenignHealthDetectionReport, tenantIdDescription, pageSizeDescription, CONTINUATION_DESCRIPTION, daysDescription } from './shared.js';
+import { READ_ONLY, MAX_RESULT_SIZE_CHARS, LEAN_EVENT_FIELDS, LEAN_EVENT_OMISSION, leanFieldSelection, SUMMARY_EVENT_FIELDS, toolResultText, SessionIdSchema, isBenignHealthDetectionReport, foreignSuccessRunIds, isCorrectedForeignFailure, tenantIdDescription, pageSizeDescription, CONTINUATION_DESCRIPTION, daysDescription } from './shared.js';
 import { toolError } from './error-handler.js';
 import { lookupErrorCode } from '../error-code-catalog.js';
 import { withEventTypeNote, assertKnownDevicePropertyKeys } from '../resource-catalog.js';
@@ -534,6 +534,8 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
         // Observation coverage: what the agent could and could not see, folded from the
         // health/lifecycle events that the triage timeline below ranks low or drops.
         const coverage = buildSessionCoverage(s, allEvents);
+        // Platform runs IME's saved result proved to carry another script's exit code (D-316).
+        const foreignRuns = foreignSuccessRunIds(allEvents);
 
         let errorCount = 0;
         let warningCount = 0;
@@ -545,7 +547,8 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
           const sev = String(e.severity ?? '');
           // A compliant health-script detection mis-stamped script_failed/Error is benign —
           // exclude it so a green session's errorCount isn't inflated by routine compliance reports.
-          const benign = isBenignHealthDetectionReport(String(e.eventType ?? ''), e.data);
+          const benign = isBenignHealthDetectionReport(String(e.eventType ?? ''), e.data)
+            || isCorrectedForeignFailure(String(e.eventType ?? ''), e.data, foreignRuns);
           if (!benign && (sev === 'Error' || sev === 'Critical')) errorCount++;
           if (sev === 'Warning') warningCount++;
           const et = String(e.eventType ?? '');
@@ -571,6 +574,8 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
         const relevanceScore = (e: Partial<EnrollmentEvent>): number => {
           // Benign compliant detection mis-stamped Error → rank as info-level, not top.
           if (isBenignHealthDetectionReport(String(e.eventType ?? ''), e.data)) return 10;
+          // A failure that was another script's exit code is not a failure of this one.
+          if (isCorrectedForeignFailure(String(e.eventType ?? ''), e.data, foreignRuns)) return 10;
           const sev = SEVERITY_RANK[String(e.severity ?? '')] ?? -1;
           if (sev >= 3) return 100;                        // Error/Critical
           if (PHASE_EVENT_TYPES.has(String(e.eventType ?? ''))) return 60;
@@ -597,7 +602,10 @@ export function registerSessionTools(server: McpServer, ga: boolean, delegated:
           phase: phaseName(e.phase, s.enrollmentType),
           message: e.message,
           source: e.source,
-          ...keyEventErrorCode(e.data, e.source),
+          // The exit code on a corrected run was another script's: no catalog text for it.
+          ...(isCorrectedForeignFailure(String(e.eventType ?? ''), e.data, foreignRuns)
+            ? { correctedByImeSavedResult: true }
+            : keyEventErrorCode(e.data, e.source)),
         }));
 
         let analysis = null;

src/McpServer/autopilot-monitor-mcp/src/tools/shared.ts

@@ -75,6 +75,8 @@ export function leanFieldSelection(
 export const SUMMARY_EVENT_FIELDS =
   'eventType,severity,source,phase,timestamp,message,sequence,' +
   'data.scriptType,data.script_type,data.scriptPart,data.script_part,data.result,' +
+  // Platform-run corrections from IME's saved result (foreignSuccessRunIds below).
+  'data.runId,data.outcome,' +
   'data.rejectedSourceTimestamp,data.rejected_source_timestamp,' +
   'data.errorCode,data.exitCode,data.hresult,data.hresultFromWin32,data.hresultSymbol,' +
   'data.errorCodeInfo,data.exitCodeInfo,data.hresultInfo,data.hresultFromWin32Info,' +
@@ -125,6 +127,38 @@ export function isBenignHealthDetectionReport(
   return true;
 }
 
+/**
+ * Run ids of platform runs whose `script_failed` came from another script's end block while IME
+ * itself reported Success: `script_output_reconciliation` with outcome "foreign" and result Success
+ * (D-316 — the agent had attributed a foreign executor's exit code and output; IME's saved result
+ * proved it). The stored `script_failed` stays as written; read sides treat it like the benign
+ * detection reports above: no error count, info-level rank, no exit-code catalog text.
+ */
+export function foreignSuccessRunIds(
+  events: ReadonlyArray<{ eventType?: string | null; data?: Record<string, unknown> }>,
+): Set<string> {
+  const runs = new Set<string>();
+  for (const e of events) {
+    if (e.eventType !== 'script_output_reconciliation' || !e.data) continue;
+    if (String(e.data.outcome ?? '') !== 'foreign') continue;
+    if (String(e.data.result ?? '').toLowerCase() !== 'success') continue;
+    const runId = e.data.runId;
+    if (typeof runId === 'string' && runId.length > 0) runs.add(runId);
+  }
+  return runs;
+}
+
+/** True for a `script_failed` whose run `foreignSuccessRunIds` names. */
+export function isCorrectedForeignFailure(
+  eventType: string | undefined,
+  data: Record<string, unknown> | undefined,
+  foreignRuns: ReadonlySet<string>,
+): boolean {
+  if (eventType !== 'script_failed' || !data || foreignRuns.size === 0) return false;
+  const runId = data.runId;
+  return typeof runId === 'string' && foreignRuns.has(runId);
+}
+
 /**
  * Builds the role-aware description for a tenant-boundable tool's `tenantId` argument. MCP clients weigh
  * the per-arg schema heavily, so a delegated (MSP) caller — for whom omitting tenantId is REJECTED, not

src/Shared/AutopilotMonitor.Shared/Constants.cs

@@ -543,6 +543,13 @@ namespace AutopilotMonitor.Shared
             // policies on its own schedule for as long as the device is up; the first run and
             // every run with a different result are still emitted in full.
             public const string ScriptRecurrenceSummary = "script_recurrence_summary";
+            // A platform script's emitted output disagreed with IME's own saved result
+            // (HKLM\...\IntuneManagementExtension\Policies\<user>\<policy>, written after IME reported the
+            // script batch): Data.outcome "foreign" (Warning, immediate upload — the run had been given
+            // another executor's end block; Data.stdout/stderr replace it, the exit code is unverified) or
+            // "repaired" (Info — the log had delivered the output incomplete). Data.runId names the corrected
+            // script_completed/script_failed. Observability only, never DecisionEngine input.
+            public const string ScriptOutputReconciliation = "script_output_reconciliation";
             // One-shot per agent run: the IME adapter detected replayed log content from a
             // previous enrollment (source lines > 24 h stale, e.g. IME logs surviving a
             // re-enrollment) and suppressed the historic script (script_started/completed/
@@ -651,7 +658,7 @@ namespace AutopilotMonitor.Shared
             // update page (CXID OobeNDUP / RebootNDUP) and its ExpeditedUpdate_* event names, plus the
             // registry state behind it (NDUP keys and both ESP "Install Windows quality updates"
             // policy paths). Bounded per agent run.
-            public const string OobeUpdatePage            = "oobe_update_page";              // Shell-Core 62404/62405 of an NDUP page, 62406/62407 update-page names — Data.cxhEvent+page+result+name(+value: boolean/integer/HRESULT only)
+            public const string OobeUpdatePage            = "oobe_update_page";              // Shell-Core 62404/62405 of an NDUP page, 62406/62407 update-page names — Data.cxhEvent+page+result+name(+value: boolean/integer/HRESULT only); cxhEvent names_capped = the run's later names were not sent
             public const string OobeUpdateState           = "oobe_update_state";             // NDUP + ESP-policy registry values at agent start/stop and at the update page — Data.moment + one entry per key alias; only when values exist and changed
             // Corroboration snapshots (gather rules, config-delivered). Secondary evidence that an
             // update landed during enrollment even when the watcher's backfill window missed it.
@@ -913,6 +920,46 @@ namespace AutopilotMonitor.Shared
             /// author-defined (no error-code enrichment unless <see cref="GatherRuleDataKeys.EnrichErrorCodes"/>).
             /// </summary>
             public const string GatherRuleExecutor = "GatherRuleExecutor";
+
+            /// <summary>Clock steps and sleep episodes from the Windows System log.</summary>
+            public const string SystemTimelineWatcher = "SystemTimelineWatcher";
+
+            /// <summary>Windows Update client events (System and Operational log).</summary>
+            public const string WindowsUpdateWatcher = "WindowsUpdateWatcher";
+
+            /// <summary>CBS servicing steps from the Setup log.</summary>
+            public const string ServicingWatcher = "ServicingWatcher";
+
+            /// <summary>
+            /// The OOBE update page telemetry from the Shell-Core log (<c>oobe_update_page</c>,
+            /// <c>oobe_update_state</c>). The ESP and Hello signals read from the same log carry
+            /// the source "EspAndHelloTracker".
+            /// </summary>
+            public const string ShellCoreTracker = "ShellCoreTracker";
+
+            /// <summary>
+            /// Sources whose rows never set a session's start. Their watchers backfill the Windows
+            /// event logs with the original event time — clock steps and sleep up to 24 h, update
+            /// and servicing activity and the update page up to 60 min before the agent started —
+            /// so their earliest row is environment observation from before the enrollment, not
+            /// its first step. Every place that derives the start from events applies this list:
+            /// backend ingest and the Events-table probe, and the portal's session duration via
+            /// shared-manifests.json.
+            /// </summary>
+            public static readonly string[] SessionAnchorIneligible =
+            {
+                SystemTimelineWatcher,
+                WindowsUpdateWatcher,
+                ServicingWatcher,
+                ShellCoreTracker,
+            };
+
+            /// <summary>
+            /// False for <see cref="SessionAnchorIneligible"/> sources; true otherwise, including a
+            /// row without a source.
+            /// </summary>
+            public static bool IsSessionAnchorEligible(string? source) =>
+                System.Array.IndexOf(SessionAnchorIneligible, source) < 0;
         }
 
         /// <summary>

src/Shared/AutopilotMonitor.Shared/Models/Metrics/SessionTimeBreakdown.cs

@@ -18,10 +18,11 @@ namespace AutopilotMonitor.Shared.Models
         public const string EspApps = "esp_apps";
 
         /// <summary>
-        /// The OOBE quality update (D-310): from the start of the update page that installed an
-        /// update to the last update evidence before the user is back — download, install, the
-        /// restarts and the servicing after them. Takes the time from the phase segment it
-        /// overlaps; one <see cref="OsUpdateSpan"/> per interval names the packages.
+        /// The OOBE quality update (D-310): from the start of the update page that worked on an
+        /// update — or, when the agent started after the page, from the update's first evidence —
+        /// to the last update evidence before the user is back: download, install, the restarts
+        /// and the servicing after them. Takes the time from the phase segment it overlaps; one
+        /// <see cref="OsUpdateSpan"/> per interval names the packages and the outcome.
         /// </summary>
         public const string OsUpdate = "os_update";
 
@@ -196,13 +197,40 @@ namespace AutopilotMonitor.Shared.Models
         /// <summary>In-window seconds of the interval.</summary>
         public int Seconds { get; set; }
 
-        /// <summary>KB numbers of the packages Windows serviced in the interval ("KB5129195"), in order of first appearance; empty when no package named one.</summary>
+        /// <summary>KB numbers of the packages that reached "Installed" in the interval ("KB5129195"), in order of first appearance; empty when none did or no package named one.</summary>
         public List<string> Kbs { get; set; } = new List<string>();
 
+        /// <summary>KB numbers of the packages Windows serviced in the interval without reaching "Installed" (for example only staged before a failed download).</summary>
+        public List<string> NotInstalledKbs { get; set; } = new List<string>();
+
+        /// <summary>How the update ended — one of <see cref="OsUpdateOutcomes"/>; the latest outcome evidence in the interval decides.</summary>
+        public string Outcome { get; set; } = OsUpdateOutcomes.Unknown;
+
         /// <summary>Restarts that began inside the interval.</summary>
         public int RebootCount { get; set; }
     }
 
+    /// <summary>
+    /// Outcome of an OOBE quality update (<see cref="OsUpdateSpan.Outcome"/>), decided by the
+    /// latest outcome evidence in its interval. Exported to the portal via shared-manifests.json.
+    /// </summary>
+    public static class OsUpdateOutcomes
+    {
+        /// <summary>A package reached "Installed", or the update page reported the install as succeeded.</summary>
+        public const string Installed = "installed";
+
+        /// <summary>The update page or servicing reported the download or install as failed.</summary>
+        public const string Failed = "failed";
+
+        /// <summary>Someone selected Skip on the update page; the update was not installed.</summary>
+        public const string Skipped = "skipped";
+
+        /// <summary>No outcome evidence before the interval ended (for example the session ended first).</summary>
+        public const string Unknown = "unknown";
+
+        public static readonly string[] All = { Installed, Failed, Skipped, Unknown };
+    }
+
     /// <summary>
     /// Per-session enrollment time attribution (F1, insights spec) — an exact partition of the
     /// session's authoritative wall clock into named segments plus an explicit unattributed

src/Web/autopilot-monitor-web/app/admin/components/TenantAdminSection.tsx

@@ -170,44 +170,37 @@ export function TenantAdminSection({
   };
 
   return (
-    <div className="bg-purple-50 border border-purple-200 rounded-lg p-4">
-      <div className="flex items-start space-x-3">
-        <svg className="w-5 h-5 text-purple-600 mt-0.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-          <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4.354a4 4 0 110 5.292M15 21H3v-1a6 6 0 0112 0v1zm0 0h6v-1a6 6 0 00-9-5.197M13 7a4 4 0 11-8 0 4 4 0 018 0z" />
-        </svg>
-        <div className="flex-1 min-w-0 space-y-4">
-          <p className="font-semibold text-purple-900">
-            Members
-            {loadingAdmins && <span className="ml-2 text-sm font-normal text-purple-700">(Loading...)</span>}
-          </p>
+    <div className="bg-purple-50 border border-purple-200 rounded-lg p-4 space-y-4">
+      <h3 className="font-semibold text-purple-900">
+        Members
+        {loadingAdmins && <span className="ml-2 text-sm font-normal text-purple-700">(Loading...)</span>}
+      </h3>
 
-          <AddMemberForm
-            value={newAdminEmail}
-            onValueChange={setNewAdminEmail}
-            role={newMemberRole}
-            onRoleChange={setNewMemberRole}
-            kind={newMemberKind}
-            onKindChange={setNewMemberKind}
-            adding={addingAdmin}
-            onAdd={handleAddTenantAdmin}
-            disabled={!canMutate}
-            stacked
-          />
+      <AddMemberForm
+        value={newAdminEmail}
+        onValueChange={setNewAdminEmail}
+        role={newMemberRole}
+        onRoleChange={setNewMemberRole}
+        kind={newMemberKind}
+        onKindChange={setNewMemberKind}
+        adding={addingAdmin}
+        onAdd={handleAddTenantAdmin}
+        disabled={!canMutate}
+        stacked
+      />
 
-          {/* key: a tenant switch starts on page 1 with no filter, search or open row. */}
-          <MemberList
-            key={tenantId}
-            members={tenantAdmins}
-            loading={loadingAdmins}
-            canMutate={canMutate}
-            removingUpn={removingAdmin}
-            updatingUpn={togglingAdmin}
-            onRemove={handleRemoveTenantAdmin}
-            onToggleEnabled={handleToggleTenantAdmin}
-            onUpdatePermissions={handleUpdatePermissions}
-          />
-        </div>
-      </div>
+      {/* key: a tenant switch starts on page 1 with no filter, search or open row. */}
+      <MemberList
+        key={tenantId}
+        members={tenantAdmins}
+        loading={loadingAdmins}
+        canMutate={canMutate}
+        removingUpn={removingAdmin}
+        updatingUpn={togglingAdmin}
+        onRemove={handleRemoveTenantAdmin}
+        onToggleEnabled={handleToggleTenantAdmin}
+        onUpdatePermissions={handleUpdatePermissions}
+      />
     </div>
   );
 }

src/Web/autopilot-monitor-web/app/admin/tenants/sections/SectionTenantConfigReport.tsx

@@ -88,6 +88,10 @@ function formatByKind(kind: RowKind | undefined, value: unknown): string {
 
 // ── Row and section primitives ───────────────────────────────────────────────
 
+// Heavier rule between grouped rows. It sits on the cell: the section tbody's divide utility overrides
+// a row's border width and color, while the collapsed table border keeps the wider cell edge.
+const GROUP_SEPARATOR = 'border-t-2 border-gray-200 dark:border-gray-600';
+
 interface ConfigRowProps {
   label: string;
   display: string;
@@ -185,8 +189,8 @@ function ChannelRows({ config }: { config: TenantConfiguration }) {
   return (
     <>
       {channels.map((ch, i) => (
-        <tr key={ch.id ?? i} className={i > 0 ? 'border-t-2 border-gray-200 dark:border-gray-600' : ''}>
-          <td colSpan={2} className="p-0">
+        <tr key={ch.id ?? i}>
+          <td colSpan={2} className={`p-0 ${i > 0 ? GROUP_SEPARATOR : ''}`}>
             <table className="w-full">
               <tbody className="divide-y divide-gray-100 dark:divide-gray-700">
                 <ConfigRow label="Channel" display={`${ch.name || ch.id}${ch.enabled === false ? ' (disabled)' : ''}`} />
@@ -214,8 +218,8 @@ function SelfHostedAiClientRows({ list }: { list: McpClientRegistrationListRespo
       <ConfigRow label="Self-hosted AI (platform switch)" display={list.enabled ? 'On' : 'Off'} />
       {list.registrations.length === 0 && <ConfigRow label="Self-hosted AI Clients" display="—" />}
       {list.registrations.map((r) => (
-        <tr key={r.registrationId} className="border-t-2 border-gray-200 dark:border-gray-600">
-          <td colSpan={2} className="p-0">
+        <tr key={r.registrationId}>
+          <td colSpan={2} className={`p-0 ${GROUP_SEPARATOR}`}>
             <table className="w-full">
               <tbody className="divide-y divide-gray-100 dark:divide-gray-700">
                 <ConfigRow label="Self-hosted AI Client" display={r.name} />

src/Web/autopilot-monitor-web/app/gather-rules/eventTypes.ts

@@ -152,6 +152,8 @@ export const KNOWN_EVENT_TYPES: EventTypeEntry[] = [
     description: "A platform script completed, or one phase (detection / remediation / post-detection) of a health script completed. Health scripts emit up to three of these per policy run." },
   { value: "script_failed", label: "script_failed", category: "script",
     description: "A platform script crashed (exit code != 0), or the remediation phase of a health script crashed. Health-script detection / post-detection phases use exit code as a compliance verdict (non-zero = non-compliant) and emit script_completed even on non-zero exit; only a true script crash in those phases would surface here." },
+  { value: "script_output_reconciliation", label: "script_output_reconciliation", category: "script",
+    description: "A platform script's reported output disagreed with the result IME saved after reporting the script batch. Outcome \"foreign\" (Warning): the run had been given another script's output and exit code; the saved output replaces it and the exit code is unknown. Outcome \"repaired\" (Info): the output had arrived incomplete. Carries runId (the corrected run), policyId, outcome, reason, result, stdout and stderr." },
   { value: "script_timeout_suspected", label: "script_timeout_suspected", category: "script",
     description: "A platform script ran to the IME script-execution timeout (~30 min; threshold 25 min) and was marked Failed while the enrollment was in progress. IME runs platform scripts serially, so a hung script starves app installs and the Autopilot-Monitor bootstrap — the prime suspect behind a late agent start / pre-failed ESP. Advisory (one per policyId); carries durationSeconds, exitCode and espPhase." },
   { value: "script_recurrence_summary", label: "script_recurrence_summary", category: "script",

src/Web/autopilot-monitor-web/app/geographic-performance/page.tsx

@@ -436,8 +436,8 @@ export default function GeographicPerformancePage() {
                           key={loc.locationKey}
                           id={`loc-${loc.locationKey.replace(/[^a-zA-Z0-9]/g, "-")}`}
                           className={`hover:bg-gray-50 transition-colors cursor-pointer ${
-                            loc.isOutlier ? "border-l-4 border-l-red-400" : ""
-                          } ${selectedLocation === loc.locationKey ? "bg-blue-50" : ""}`}
+                            selectedLocation === loc.locationKey ? "bg-blue-50" : ""
+                          }`}
                           onClick={() => {
                             const days = timeRange === "7d" ? 7 : timeRange === "30d" ? 30 : 90;
                             // Carry the selected tenant into the drill-in so a cross-tenant caller (GA override
@@ -447,7 +447,8 @@ export default function GeographicPerformancePage() {
                           }}
                           onMouseEnter={() => setSelectedLocation(loc.locationKey)}
                         >
-                          <td className="px-4 py-3 text-sm text-gray-900">
+                          {/* Outlier accent on the cell, not the row: the tbody's divide color overrides a row's border-color. */}
+                          <td className={`px-4 py-3 text-sm text-gray-900 ${loc.isOutlier ? "border-l-4 border-l-red-400" : ""}`}>
                             <div className="flex items-center">
                               <span className="font-medium">{loc.locationKey}</span>
                               {loc.isOutlier && (

src/Web/autopilot-monitor-web/app/page.tsx

@@ -1,41 +1,17 @@
-import { AuthGate } from "../components/landing/AuthGate";
-import { LandingNavbar } from "../components/landing/LandingNavbar";
-import { Hero } from "../components/landing/Hero";
-import { StatsBand } from "../components/landing/StatsBand";
-import { JustAsk } from "../components/landing/JustAsk";
-import { Story } from "../components/landing/Story";
-import { CapabilitiesStrip } from "../components/landing/CapabilitiesStrip";
-import { Comparison } from "../components/landing/Comparison";
-import { HowItWorks } from "../components/landing/HowItWorks";
-import { Testimonials } from "../components/landing/Testimonials";
-import { FinalCta } from "../components/landing/FinalCta";
-import { SiteFooter } from "../components/SiteFooter";
-import { MarketingTracker } from "../components/MarketingTracker";
+import { LandingPage } from "../components/landing/LandingPage";
+import { loadPlatformStatsSnapshot } from "../lib/platformStats";
+
+// The stats read below runs once per `next build` and bypasses Next's fetch cache (`no-store`,
+// see lib/platformStats.ts). force-static keeps that legal in the static export; the landing
+// tree reads no request-time API (cookies, headers, search params) that it would blank out.
+export const dynamic = "force-static";
 
 /**
- * Landing page v2 — a scroll story of one enrollment.
- * All theming goes through the lp-* tokens (globals.css); sections live
- * in components/landing/. Auth behavior (AuthGate redirect, LoginButton
- * portal handoff) is unchanged from v1.
+ * The landing page with the platform stats of the build baked into its static HTML, so
+ * crawlers and LLM fetchers that run no JS see the numbers too; browsers then load the live
+ * ones (components/landing/StatsBand.tsx). Awaited here, not under a Suspense boundary: React
+ * would move a resolved boundary of a page this size into a hidden div at the end of the body.
  */
-export default function LandingPage() {
-  return (
-    <div className="landing-v2 min-h-screen bg-[var(--lp-bg)]">
-      {/* Client component: handles auth redirect + loading overlay */}
-      <AuthGate />
-      <MarketingTracker page="landing">
-        <LandingNavbar />
-        <Hero />
-        <StatsBand />
-        <JustAsk />
-        <Story />
-        <CapabilitiesStrip />
-        <Comparison />
-        <HowItWorks />
-        <Testimonials />
-        <FinalCta />
-        <SiteFooter />
-      </MarketingTracker>
-    </div>
-  );
+export default async function Page() {
+  return <LandingPage statsSnapshot={await loadPlatformStatsSnapshot()} />;
 }

src/Web/autopilot-monitor-web/app/sessions/components/EventTimeline.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState, useMemo, useDeferredValue } from "react";
+import { createContext, useContext, useState, useMemo, useDeferredValue } from "react";
 import { EnrollmentEvent, Session } from "@/types";
 import { normalizeEventDataForDisplay, shortenBuildHashInMessage } from "../utils/eventHelpers";
 import { buildEventSearchMatcher, formatEventSearchTerm, parseEventSearchQuery } from "../utils/eventSearchQuery";
@@ -8,6 +8,11 @@ import { getEnrichedOrLookup, formatErrorCode, errorCodeTooltip, type ErrorCodeI
 import { readTimeProvenance, classifyTimeJump, readClockChangeDeltaMs } from "@/lib/timeProvenance";
 import { isRebootOrRetryClass } from "@/lib/installProgress";
 import { formatDuration, formatUtcOffset } from "@/lib/formatting";
+import { SCRIPT_OUTPUT_RECONCILIATION } from "@/lib/scriptExecutions";
+
+// runId → outcome of every platform run that IME's saved result corrected later (D-316): the
+// run's own row says so, so its emitted output is never read as the script's.
+const CorrectedRunsContext = createContext<ReadonlyMap<string, "foreign" | "repaired">>(new Map());
 
 const SEARCH_SYNTAX_HINT =
   "Searches event type, message, source and the details JSON (e.g. gather output). " +
@@ -104,10 +109,20 @@ export default function EventTimeline({
     [events],
   );
 
+  const correctedRuns = useMemo(() => {
+    const runs = new Map<string, "foreign" | "repaired">();
+    for (const e of events) {
+      if (e.eventType !== SCRIPT_OUTPUT_RECONCILIATION) continue;
+      const runId = e.data?.runId;
+      if (typeof runId === "string" && runId.length > 0) runs.set(runId, e.data?.outcome === "foreign" ? "foreign" : "repaired");
+    }
+    return runs;
+  }, [events]);
+
   const filterPhaseEvents = (phaseEvents: EnrollmentEvent[]) =>
     matchesSearch ? phaseEvents.filter(matchesSearch) : phaseEvents;
 
-  return (
+  const timeline = (
     <div className="space-y-6">
       {/* Search + Severity filters + Expand/Collapse — shared controls above the timeline(s) */}
       <div className="flex flex-col sm:flex-row sm:items-center gap-2">
@@ -356,6 +371,8 @@ export default function EventTimeline({
       )}
     </div>
   );
+
+  return <CorrectedRunsContext.Provider value={correctedRuns}>{timeline}</CorrectedRunsContext.Provider>;
 }
 
 function PhaseSection({
@@ -515,7 +532,13 @@ function EventRow({ event, showScriptOutput, prevEvent, clockDeltas }: { event:
   // timeline still applies the same script-event styling/iconography.
   const isScriptEvent = event.eventType === "script_started"
     || event.eventType === "script_completed"
-    || event.eventType === "script_failed";
+    || event.eventType === "script_failed"
+    || event.eventType === SCRIPT_OUTPUT_RECONCILIATION;
+  const correctedRuns = useContext(CorrectedRunsContext);
+  const eventRunId = event.data?.runId;
+  const laterCorrection = event.eventType !== SCRIPT_OUTPUT_RECONCILIATION && typeof eventRunId === "string"
+    ? correctedRuns.get(eventRunId)
+    : undefined;
   const detailData = useMemo(() => {
     if (!rawDetailData || !isScriptEvent || showScriptOutput !== false) return rawDetailData;
     const filtered = { ...rawDetailData };
@@ -611,6 +634,13 @@ function EventRow({ event, showScriptOutput, prevEvent, clockDeltas }: { event:
             <span className="text-sm font-medium text-gray-900">{event.eventType}</span>
           </div>
           <p className="mt-1 text-sm text-gray-600" title={event.message || undefined}>{shortenBuildHashInMessage(event.message)}</p>
+          {laterCorrection && (
+            <p className="mt-0.5 text-xs text-gray-500">
+              {laterCorrection === "foreign"
+                ? "Corrected later from IME's saved result: the output and exit code on this row belonged to another script."
+                : "Output completed later from IME's saved result."}
+            </p>
+          )}
           {/* Exit code / HRESULT badge for app install events */}
           {(event.eventType === "app_install_failed" || event.eventType === "app_install_completed") && (() => {
             const ec = (event.data?.exitCode ?? event.data?.exit_code) as string | number | undefined;

src/Web/autopilot-monitor-web/app/sessions/components/TimeAttributionLane.tsx

@@ -2,6 +2,7 @@
 
 import React from "react";
 import type { SessionTimeBreakdown } from "@/utils/wire-types.generated";
+import { osUpdateDetail } from "./timeAttributionLogic";
 
 /**
  * F1 time attribution (insights spec §F1): renders the PRE-COMPUTED breakdown row of a
@@ -85,15 +86,9 @@ export default function TimeAttributionLane({ breakdown }: { breakdown: SessionT
   }
   totals.set("unattributed", breakdown.unattributedSeconds);
 
-  // What the OOBE quality update installed and how often it restarted — named on the
-  // Windows Update slice (the server computed it; the client only joins the lists).
-  const osUpdates = breakdown.osUpdates ?? [];
-  const updateKbs = Array.from(new Set(osUpdates.flatMap(u => u.kbs ?? [])));
-  const updateRestarts = osUpdates.reduce((sum, u) => sum + (u.rebootCount ?? 0), 0);
-  const updateDetail = [
-    updateKbs.join(", "),
-    updateRestarts > 0 ? `${updateRestarts} restart${updateRestarts !== 1 ? "s" : ""}` : "",
-  ].filter(Boolean).join(" · ");
+  // How the OOBE quality update ended, what it installed and how often it restarted — named on
+  // the Windows Update slice.
+  const updateDetail = osUpdateDetail(breakdown.osUpdates ?? []);
 
   const parts = SEGMENT_META
     .map(meta => ({

src/Web/autopilot-monitor-web/app/sessions/components/__tests__/timeAttributionLogic.test.ts

@@ -0,0 +1,39 @@
+import { describe, expect, it } from "vitest";
+import { SHARED_MANIFEST } from "@/utils/shared-manifests.generated";
+import { osUpdateDetail } from "../timeAttributionLogic";
+
+describe("osUpdateDetail", () => {
+  it("names the outcome, the installed KBs and the restarts of an installed update", () => {
+    expect(osUpdateDetail([
+      { outcome: "installed", kbs: ["KB5124007", "KB5129195", "KB5054156"], notInstalledKbs: [], rebootCount: 2 },
+    ])).toBe("installed · KB5124007, KB5129195, KB5054156 · 2 restarts");
+  });
+
+  it("names a failed update's staged KB as not installed", () => {
+    // Field shape e7551b82: only the servicing stack was staged before the download failed.
+    expect(osUpdateDetail([
+      { outcome: "failed", kbs: [], notInstalledKbs: ["KB5124007"], rebootCount: 1 },
+    ])).toBe("failed · not installed: KB5124007 · 1 restart");
+  });
+
+  it("names a skipped update", () => {
+    expect(osUpdateDetail([{ outcome: "skipped", kbs: [], notInstalledKbs: [], rebootCount: 0 }])).toBe("skipped");
+  });
+
+  it("names no outcome for an unknown one or a row written before the outcome existed", () => {
+    expect(osUpdateDetail([{ outcome: "unknown", kbs: ["KB5129195"], rebootCount: 0 }])).toBe("KB5129195");
+    expect(osUpdateDetail([{ kbs: ["KB5129195"], rebootCount: 3 }])).toBe("KB5129195 · 3 restarts");
+  });
+
+  it("is empty without updates", () => {
+    expect(osUpdateDetail([])).toBe("");
+  });
+
+  it("labels every outcome the backend can send", () => {
+    // A new backend outcome must get its words here, not fall through as unnamed.
+    for (const outcome of SHARED_MANIFEST.osUpdateOutcomes) {
+      const detail = osUpdateDetail([{ outcome, kbs: [], notInstalledKbs: [], rebootCount: 0 }]);
+      expect(detail).toBe(outcome === "unknown" ? "" : outcome);
+    }
+  });
+});

src/Web/autopilot-monitor-web/app/sessions/components/timeAttributionLogic.ts

@@ -0,0 +1,37 @@
+import type { OsUpdateSpan } from "@/utils/wire-types.generated";
+import { SHARED_MANIFEST } from "@/utils/shared-manifests.generated";
+
+/** How an OOBE quality update ended (backend `OsUpdateOutcomes`). */
+export type OsUpdateOutcome = (typeof SHARED_MANIFEST.osUpdateOutcomes)[number];
+
+/** The words the Windows Update slice names an outcome with; "unknown" names nothing. */
+const OUTCOME_LABELS: Record<OsUpdateOutcome, string | null> = {
+  installed: "installed",
+  failed: "failed",
+  skipped: "skipped",
+  unknown: null,
+};
+
+/**
+ * What the OOBE quality update did, for the Windows Update slice: the outcome, the KBs that
+ * reached "Installed", the ones it serviced without installing, and its restarts — e.g.
+ * "failed · not installed: KB5124007 · 1 restart". The server computed every part; this only
+ * joins the lists. Rows written before the outcome existed carry none and name no outcome.
+ */
+export function osUpdateDetail(osUpdates: ReadonlyArray<Partial<OsUpdateSpan>>): string {
+  const outcomes = distinct(osUpdates.map(u => OUTCOME_LABELS[u.outcome as OsUpdateOutcome] ?? null));
+  const installed = distinct(osUpdates.flatMap(u => u.kbs ?? []));
+  const notInstalled = distinct(osUpdates.flatMap(u => u.notInstalledKbs ?? []));
+  const restarts = osUpdates.reduce((sum, u) => sum + (u.rebootCount ?? 0), 0);
+
+  return [
+    outcomes.join(", "),
+    installed.join(", "),
+    notInstalled.length > 0 ? `not installed: ${notInstalled.join(", ")}` : "",
+    restarts > 0 ? `${restarts} restart${restarts !== 1 ? "s" : ""}` : "",
+  ].filter(Boolean).join(" · ");
+}
+
+function distinct(values: ReadonlyArray<string | null>): string[] {
+  return Array.from(new Set(values.filter((v): v is string => !!v)));
+}

src/Web/autopilot-monitor-web/app/sessions/page.tsx

@@ -234,6 +234,8 @@ function SessionDetailContent() {
       e => e.eventType === "script_started"
         || e.eventType === "script_completed"
         || e.eventType === "script_failed"
+        // Corrections of a platform run from IME's saved result (D-316) — applied by the reducer.
+        || e.eventType === "script_output_reconciliation"
     ),
     [events]
   );

src/Web/autopilot-monitor-web/components/Navbar.tsx

@@ -298,9 +298,10 @@ export default function Navbar() {
                       </div>
                     ) : (
                       <div className="divide-y divide-gray-100">
+                        {/* Row accents are inset shadows, not border-l: the divide color overrides a child's border-color on every row but the first. */}
                         {/* Tenant-scoped persistent notifications (e.g. hardware rejections) — top */}
                         {tenantNotifications.map((tn) => (
-                          <div key={`tn-${tn.id}`} className={`px-4 py-3 hover:bg-blue-50/50 dark:hover:bg-blue-900/45 transition-colors border-l-4 border-blue-500 bg-blue-50/30 dark:bg-blue-900/20 ${tn.href ? 'cursor-pointer' : ''}`} onClick={() => { if (tn.href) openNotificationHref(tn.href); }}>
+                          <div key={`tn-${tn.id}`} className={`px-4 py-3 hover:bg-blue-50/50 dark:hover:bg-blue-900/45 transition-colors shadow-[inset_4px_0_0_0] shadow-blue-500 bg-blue-50/30 dark:bg-blue-900/20 ${tn.href ? 'cursor-pointer' : ''}`} onClick={() => { if (tn.href) openNotificationHref(tn.href); }}>
                             <div className="flex items-start justify-between">
                               <div className="flex items-start space-x-2.5 flex-1">
                                 <span className="text-lg">{tn.type === 'hardware_rejection' ? '🖥️' : '🔔'}</span>
@@ -333,7 +334,7 @@ export default function Navbar() {
                         ))}
                         {/* Persistent Global Admin Notifications */}
                         {visibleGlobal.map((gn) => (
-                          <div key={`ga-${gn.id}`} className={`px-4 py-3 hover:bg-purple-50/50 dark:hover:bg-purple-900/45 transition-colors border-l-4 border-purple-500 bg-purple-50/30 dark:bg-purple-900/20 ${gn.href ? 'cursor-pointer' : ''}`} onClick={() => { if (gn.href) openNotificationHref(gn.href); }}>
+                          <div key={`ga-${gn.id}`} className={`px-4 py-3 hover:bg-purple-50/50 dark:hover:bg-purple-900/45 transition-colors shadow-[inset_4px_0_0_0] shadow-purple-500 bg-purple-50/30 dark:bg-purple-900/20 ${gn.href ? 'cursor-pointer' : ''}`} onClick={() => { if (gn.href) openNotificationHref(gn.href); }}>
                             <div className="flex items-start justify-between">
                               <div className="flex items-start space-x-2.5 flex-1">
                                 <span className="text-lg">{gn.type === 'session_report' ? '\uD83D\uDCCB' : '\uD83C\uDF1F'}</span>

src/Web/autopilot-monitor-web/components/ScriptExecutions.tsx

@@ -30,6 +30,14 @@ import PhaseDivider from "@/components/PhaseDivider";
 // span is hours of offset error rather than run time (a 10 s script once read "1h 00m").
 const DURATION_SUPPRESSED_TITLE = "Run time not measurable: the start and end log lines were resolved on different timezone assumptions, so their span would be offset error, not run time";
 
+// IME's saved result corrected the run (script_output_reconciliation): the log had attributed
+// another script's end block to it, so its exit code is unknown and the output shown is IME's.
+const EXIT_UNVERIFIED_TITLE = "Exit code unknown: the IME log had attributed another script's output and exit code to this run. The output shown is this script's own, as IME saved it.";
+const OUTPUT_CORRECTED_TITLE: Record<"foreign" | "repaired", string> = {
+  foreign: "The IME log had attributed another script's output to this run. This is the script's own output, as IME saved it after reporting the result.",
+  repaired: "The IME log delivered this output incomplete. This is the full output, as IME saved it after reporting the result.",
+};
+
 interface ScriptExecutionsProps {
   events: ScriptInputEvent[];
   showScriptOutput?: boolean;
@@ -528,6 +536,9 @@ function ScriptItemRow({ item, showScriptOutput, latestBootstrapVersion, nested,
               exit {item.exitCode}
             </span>
           )}
+          {item.exitCode == null && item.outputCorrection === "foreign" && (
+            <span className="font-mono text-gray-400" title={EXIT_UNVERIFIED_TITLE}>exit n/a</span>
+          )}
           {durationLabel && (
             <span
               className={`font-mono ${isSlowDuration ? "text-amber-600 font-medium" : "text-gray-500"}`}
@@ -564,6 +575,9 @@ function ScriptItemRow({ item, showScriptOutput, latestBootstrapVersion, nested,
             {!nested && item.runContext && <span><span className="font-medium text-gray-700">Context:</span> {item.runContext}</span>}
             {!nested && item.targetType != null && <span><span className="font-medium text-gray-700">Target:</span> {item.targetType === 2 ? "Device" : "User"}</span>}
             {item.exitCode != null && <span><span className="font-medium text-gray-700">Exit Code:</span> <span className="font-mono">{item.exitCode}</span></span>}
+            {item.exitCode == null && item.outputCorrection === "foreign" && (
+              <span title={EXIT_UNVERIFIED_TITLE}><span className="font-medium text-gray-700">Exit Code:</span> <span className="font-mono text-gray-400">n/a</span></span>
+            )}
             {detailDurationLabel && <span><span className="font-medium text-gray-700">Duration:</span> <span className={`font-mono ${isSlowDuration ? "text-amber-600" : ""}`}>{detailDurationLabel}</span></span>}
             {!detailDurationLabel && item.durationSuppressedReason && (
               <span title={DURATION_SUPPRESSED_TITLE}><span className="font-medium text-gray-700">Duration:</span> <span className="font-mono text-gray-400">n/a</span></span>
@@ -601,7 +615,12 @@ function ScriptItemRow({ item, showScriptOutput, latestBootstrapVersion, nested,
 
           {hasStdout && (
             <div>
-              <div className="text-xs font-medium text-gray-500 mb-1">stdout</div>
+              <div className="text-xs font-medium text-gray-500 mb-1">
+                stdout
+                {item.outputCorrection && (
+                  <span className="font-normal text-gray-400" title={OUTPUT_CORRECTED_TITLE[item.outputCorrection]}>{" · from IME's saved result"}</span>
+                )}
+              </div>
               <div className="p-2 bg-gray-900 rounded text-xs text-gray-100 font-mono overflow-x-auto max-h-48 overflow-y-auto">
                 <pre className="whitespace-pre-wrap break-words">{item.stdout}</pre>
               </div>
@@ -614,7 +633,12 @@ function ScriptItemRow({ item, showScriptOutput, latestBootstrapVersion, nested,
 
           {hasStderr && (
             <div>
-              <div className="text-xs font-medium text-red-500 mb-1">stderr</div>
+              <div className="text-xs font-medium text-red-500 mb-1">
+                stderr
+                {item.outputCorrection && (
+                  <span className="font-normal text-gray-400" title={OUTPUT_CORRECTED_TITLE[item.outputCorrection]}>{" · from IME's saved result"}</span>
+                )}
+              </div>
               <div className="p-2 bg-gray-900 rounded text-xs text-red-300 font-mono overflow-x-auto max-h-48 overflow-y-auto">
                 <pre className="whitespace-pre-wrap break-words">{item.stderr}</pre>
               </div>

src/Web/autopilot-monitor-web/components/__tests__/landingStats.test.ts

@@ -0,0 +1,67 @@
+import { describe, it, expect, vi } from "vitest";
+import { createElement } from "react";
+import { renderToStaticMarkup } from "react-dom/server";
+import { prerender } from "react-dom/static";
+
+// LandingNavbar and LoginButton read the auth context; the public pages render signed out.
+vi.mock("@/contexts/AuthContext", () => ({
+  useAuth: () => ({ login: async () => undefined, isAuthenticated: false, user: null, getAccessToken: async () => null }),
+}));
+// AuthGate only redirects signed-in visitors (it needs the app router) and renders no links.
+vi.mock("@/components/landing/AuthGate", () => ({ AuthGate: () => null }));
+
+const { SNAPSHOT } = vi.hoisted(() => ({
+  SNAPSHOT: {
+    items: [
+      { label: "enrollments monitored", value: "12,481" },
+      { label: "events processed", value: "8.3M" },
+    ],
+    asOf: "2026-10-02T14:00:03.1234567Z",
+  },
+}));
+// The blob read itself is covered in lib/__tests__/platformStats.test.ts.
+vi.mock("@/lib/platformStats", async importOriginal => ({
+  ...(await importOriginal<typeof import("@/lib/platformStats")>()),
+  loadPlatformStatsSnapshot: async () => SNAPSHOT,
+}));
+
+import LandingRoute from "@/app/page";
+import { StatsBand } from "@/components/landing/StatsBand";
+
+/**
+ * Crawlers and LLM fetchers run no JS: the platform stats only reach them when the build renders
+ * the numbers into the landing page's HTML (lib/platformStats.ts, app/page.tsx).
+ */
+describe("platform stats in the landing page's static HTML", () => {
+  it("the band renders the baked numbers and marks the snapshot", () => {
+    const html = renderToStaticMarkup(createElement(StatsBand, { snapshot: SNAPSHOT }));
+    expect(html).toContain(">12,481<");
+    expect(html).toContain(">enrollments monitored<");
+    expect(html).toContain(">8.3M<");
+    expect(html).toContain(`data-stats-snapshot="${SNAPSHOT.asOf}"`);
+    expect(html).not.toContain("animate-pulse");
+  });
+
+  it("without a snapshot the band shows the loading skeleton and no marker", () => {
+    const html = renderToStaticMarkup(createElement(StatsBand, { snapshot: null }));
+    expect(html).toContain('data-track-section="stats"');
+    expect(html).toContain("animate-pulse");
+    expect(html).not.toContain("data-stats-snapshot");
+  });
+
+  // A Suspense boundary around the read would still resolve at build time, but React moves a
+  // resolved boundary of a page this size into a hidden div at the end of the body.
+  it("the page renders the numbers in place, not in a hidden streaming segment", async () => {
+    const { prelude } = await prerender(createElement(LandingRoute));
+    const html = await new Response(prelude).text();
+
+    const bandStart = html.indexOf('data-track-section="stats"');
+    const nextSection = html.indexOf('data-track-section="just_ask"');
+    const figure = html.indexOf(">12,481<");
+    expect(bandStart).toBeGreaterThan(-1);
+    expect(figure).toBeGreaterThan(bandStart);
+    expect(figure).toBeLessThan(nextSection);
+    expect(html).toContain(`data-stats-snapshot="${SNAPSHOT.asOf}"`);
+    expect(html).not.toMatch(/<div hidden id="S:/);
+  });
+});

src/Web/autopilot-monitor-web/components/__tests__/marketingLinks.guard.test.ts

@@ -9,7 +9,7 @@ vi.mock("@/contexts/AuthContext", () => ({
 // AuthGate only redirects signed-in visitors (it needs the app router) and renders no links.
 vi.mock("@/components/landing/AuthGate", () => ({ AuthGate: () => null }));
 
-import LandingPage from "@/app/page";
+import { LandingPage } from "@/components/landing/LandingPage";
 import GetStartedPage from "@/app/get-started/page";
 import AiPage from "@/app/ai/page";
 import AboutPage from "@/app/about/page";
@@ -25,7 +25,8 @@ import TermsPage from "@/app/terms/page";
  */
 
 const PAGES: Record<string, ComponentType> = {
-  landing: LandingPage,
+  // app/page.tsx only awaits the build-time stats and renders this body; the sync renderer cannot await.
+  landing: () => createElement(LandingPage, { statsSnapshot: null }),
   "get-started": GetStartedPage,
   ai: AiPage,
   about: AboutPage,

src/Web/autopilot-monitor-web/components/__tests__/marketingTracking.guard.test.ts

@@ -11,7 +11,7 @@ vi.mock("@/contexts/AuthContext", () => ({
 // AuthGate only redirects signed-in visitors (it needs the app router) and renders no links.
 vi.mock("@/components/landing/AuthGate", () => ({ AuthGate: () => null }));
 
-import LandingPage from "@/app/page";
+import { LandingPage } from "@/components/landing/LandingPage";
 import GetStartedPage from "@/app/get-started/page";
 import AiPage from "@/app/ai/page";
 import robots from "@/app/robots";
@@ -27,6 +27,8 @@ import { sitePageUrl } from "@/utils/config";
  */
 
 const render = (Page: ComponentType) => renderToStaticMarkup(createElement(Page));
+// app/page.tsx only awaits the build-time stats and renders this body; the sync renderer cannot await.
+const Landing = () => createElement(LandingPage, { statsSnapshot: null });
 const trackIds = (html: string) => [...html.matchAll(/data-track="([^"]+)"/g)].map(m => m[1]);
 const sectionIds = (html: string) => [...html.matchAll(/data-track-section="([^"]+)"/g)].map(m => m[1]);
 const untracked = (html: string) =>
@@ -37,7 +39,7 @@ const untracked = (html: string) =>
 const PAGES: { name: string; Page: ComponentType; sections: string[] }[] = [
   {
     name: "landing",
-    Page: LandingPage,
+    Page: Landing,
     sections: ["hero", "stats", "just_ask", "story", "capabilities", "comparison", "how_it_works", "testimonials", "final_cta"],
   },
   { name: "get-started", Page: GetStartedPage, sections: ["steps", "signup"] },
@@ -60,7 +62,7 @@ describe("marketing page tracking", () => {
   }
 
   it("the landing links to the AI page from the navbar, Then just ask and the footer", () => {
-    const ids = trackIds(render(LandingPage));
+    const ids = trackIds(render(Landing));
     expect(ids).toEqual(expect.arrayContaining(["nav_ai", "just_ask_ai", "footer_ai"]));
   });
 

src/Web/autopilot-monitor-web/components/landing/LandingPage.tsx

@@ -0,0 +1,46 @@
+import { AuthGate } from "./AuthGate";
+import { LandingNavbar } from "./LandingNavbar";
+import { Hero } from "./Hero";
+import { StatsBand } from "./StatsBand";
+import { JustAsk } from "./JustAsk";
+import { Story } from "./Story";
+import { CapabilitiesStrip } from "./CapabilitiesStrip";
+import { Comparison } from "./Comparison";
+import { HowItWorks } from "./HowItWorks";
+import { Testimonials } from "./Testimonials";
+import { FinalCta } from "./FinalCta";
+import { SiteFooter } from "../SiteFooter";
+import { MarketingTracker } from "../MarketingTracker";
+import type { PlatformStatsSnapshot } from "@/lib/platformStats";
+
+/**
+ * Landing page v2 — a scroll story of one enrollment.
+ * All theming goes through the lp-* tokens (globals.css); sections live
+ * in components/landing/. Auth behavior (AuthGate redirect, LoginButton
+ * portal handoff) is unchanged from v1.
+ *
+ * Synchronous on purpose: app/page.tsx awaits the build-time stats and hands
+ * them in, and the marketing guard tests render this body with the sync
+ * renderToStaticMarkup.
+ */
+export function LandingPage({ statsSnapshot }: { statsSnapshot: PlatformStatsSnapshot | null }) {
+  return (
+    <div className="landing-v2 min-h-screen bg-[var(--lp-bg)]">
+      {/* Client component: handles auth redirect + loading overlay */}
+      <AuthGate />
+      <MarketingTracker page="landing">
+        <LandingNavbar />
+        <Hero />
+        <StatsBand snapshot={statsSnapshot} />
+        <JustAsk />
+        <Story />
+        <CapabilitiesStrip />
+        <Comparison />
+        <HowItWorks />
+        <Testimonials />
+        <FinalCta />
+        <SiteFooter />
+      </MarketingTracker>
+    </div>
+  );
+}

src/Web/autopilot-monitor-web/components/landing/StatsBand.tsx

@@ -1,61 +1,12 @@
 "use client";
 
 import { useEffect, useState } from "react";
-
-interface PlatformStatsManifest {
-  latest: string;
-  generatedAtUtc: string;
-}
-
-interface PlatformStatsPayload {
-  totalEnrollments?: number;
-  totalUsers?: number;
-  totalTenants?: number;
-  totalSignedUpTenants?: number;
-  uniqueDeviceModels?: number;
-  totalEventsProcessed?: number;
-  successfulEnrollments?: number;
-  issuesDetected?: number;
-  lastFullCompute?: string;
-  lastUpdated?: string;
-}
-
-function resolvePlatformStatsManifestUrl(rawUrl?: string): string {
-  const trimmed = rawUrl?.trim();
-  if (!trimmed) {
-    return "/platform-stats.json";
-  }
-
-  const hashIndex = trimmed.indexOf("#");
-  const withoutHash = hashIndex >= 0 ? trimmed.slice(0, hashIndex) : trimmed;
-  const hash = hashIndex >= 0 ? trimmed.slice(hashIndex) : "";
-
-  const queryIndex = withoutHash.indexOf("?");
-  const basePath = queryIndex >= 0 ? withoutHash.slice(0, queryIndex) : withoutHash;
-  const query = queryIndex >= 0 ? withoutHash.slice(queryIndex) : "";
-
-  if (/\.json$/i.test(basePath)) {
-    return trimmed;
-  }
-
-  const normalizedBasePath = basePath.endsWith("/") ? basePath.slice(0, -1) : basePath;
-  const manifestPath = `${normalizedBasePath}/platform-stats.json`;
-  return `${manifestPath}${query}${hash}`;
-}
-
-const PLATFORM_STATS_MANIFEST_URL =
-  resolvePlatformStatsManifestUrl(process.env.NEXT_PUBLIC_PLATFORM_STATS_MANIFEST_URL);
-
-interface StatItem {
-  label: string;
-  value: string;
-}
-
-/** 8,341,206 → "8.3M"; smaller values keep their grouped form. */
-function compact(n: number): string {
-  if (n >= 1_000_000) return `${(n / 1_000_000).toFixed(1)}M`;
-  return n.toLocaleString("en-US");
-}
+import {
+  fetchLivePlatformStats,
+  toStatItems,
+  type PlatformStatsSnapshot,
+  type StatItem,
+} from "@/lib/platformStats";
 
 /**
  * Sample values for local development only, where no stats blob is
@@ -71,81 +22,51 @@ const DEV_SAMPLE_STATS: StatItem[] = [
 ];
 
 /**
- * Full-bleed platform stats band under the hero shot. Skeleton while
- * loading; on fetch failure it shows dev sample data locally and
- * disappears entirely in production (never an endless skeleton, never
- * fake numbers).
+ * Full-bleed platform stats band under the hero shot. Starts with the
+ * numbers the build baked in (`snapshot`, lib/platformStats.ts), so the
+ * static HTML carries them for crawlers and LLM fetchers, then swaps in the
+ * live numbers. A failed live read keeps the baked numbers; without either,
+ * it shows dev sample data locally and disappears entirely in production
+ * (never an endless skeleton, never fake numbers). The skeleton only shows
+ * while a page built without a snapshot loads.
  */
-export function StatsBand() {
-  const [stats, setStats] = useState<StatItem[] | null>(null);
+export function StatsBand({ snapshot }: { snapshot: PlatformStatsSnapshot | null }) {
+  const [live, setLive] = useState<StatItem[] | null>(null);
   const [failed, setFailed] = useState(false);
 
   useEffect(() => {
     let cancelled = false;
 
-    const fail = () => {
+    const loadLiveStats = async () => {
+      const payload = await fetchLivePlatformStats();
       if (cancelled) return;
-      if (process.env.NODE_ENV === "development") {
-        setStats(DEV_SAMPLE_STATS);
+      const items = payload ? toStatItems(payload) : [];
+      if (items.length > 0) {
+        setLive(items);
       } else {
         setFailed(true);
       }
     };
 
-    const loadPlatformStats = async () => {
-      try {
-        const manifestResponse = await fetch(PLATFORM_STATS_MANIFEST_URL, { cache: "no-store" });
-        if (!manifestResponse.ok) return fail();
-
-        const manifest = (await manifestResponse.json()) as PlatformStatsManifest;
-        if (!manifest?.latest) return fail();
-
-        const versionedUrl = new URL(manifest.latest, manifestResponse.url).toString();
-        const statsResponse = await fetch(versionedUrl, { cache: "force-cache" });
-        if (!statsResponse.ok) return fail();
-
-        const payload = (await statsResponse.json()) as PlatformStatsPayload;
-        if (cancelled) return;
-
-        const items: StatItem[] = [];
-        if (payload.totalEnrollments) {
-          items.push({ label: "enrollments monitored", value: payload.totalEnrollments.toLocaleString("en-US") });
-        }
-        if (payload.issuesDetected) {
-          items.push({ label: "issues detected", value: payload.issuesDetected.toLocaleString("en-US") });
-        }
-        if (payload.totalSignedUpTenants) {
-          items.push({ label: "organisations", value: payload.totalSignedUpTenants.toLocaleString("en-US") });
-        }
-        if (payload.uniqueDeviceModels) {
-          items.push({ label: "device models", value: payload.uniqueDeviceModels.toLocaleString("en-US") });
-        }
-        if (payload.totalEventsProcessed) {
-          items.push({ label: "events processed", value: compact(payload.totalEventsProcessed) });
-        }
-        if (items.length > 0) {
-          setStats(items);
-        } else {
-          fail();
-        }
-      } catch {
-        // The band is decorative and must never break the page.
-        fail();
-      }
-    };
-
-    loadPlatformStats();
+    loadLiveStats();
     return () => {
       cancelled = true;
     };
   }, []);
 
-  if (failed) {
+  const devFallback = failed && process.env.NODE_ENV === "development" ? DEV_SAMPLE_STATS : null;
+  const stats = live ?? snapshot?.items ?? devFallback;
+  if (!stats && failed) {
     return null;
   }
 
   return (
-    <section data-track-section="stats" className="border-y border-[var(--lp-line-soft)] bg-[var(--lp-surface-2)]">
+    <section
+      data-track-section="stats"
+      // Which build snapshot the static HTML carries; deploy-web.yml warns when it is missing.
+      data-stats-snapshot={snapshot ? (snapshot.asOf ?? "") : undefined}
+      className="border-y border-[var(--lp-line-soft)] bg-[var(--lp-surface-2)]"
+    >
       <div className="max-w-7xl mx-auto px-6 grid grid-cols-2 sm:grid-cols-3 lg:grid-cols-5 gap-y-6 py-8 lg:divide-x lg:divide-[var(--lp-line)]">
         {(stats ?? Array.from({ length: 5 }, () => null)).map((item, i) =>
           item ? (

src/Web/autopilot-monitor-web/lib/__tests__/apiClient.guard.baseline.ts

@@ -6,7 +6,6 @@
 /** Files that keep a raw site for a stated reason; they never leave the baseline. */
 export const PERMANENT: Record<string, string> = {
   "contexts/AuthContext.tsx": "auth/me bootstrap runs before the auth context exists: raw fetch by design",
-  "components/landing/StatsBand.tsx": "unauthenticated public blob manifest, not the API",
   "app/health-check/page.tsx": "/version.json of the SWA itself, not the API",
   "app/dashboard/hooks/deleteSessionResponse.ts": "safeJson on the 202 Response of the delete-cascade classifier (refusals arrive as ApiError)",
   "app/settings/TenantConfigContext.tsx": "consent return path routes on TokenExpiredError (router.replace); the access check rethrows it as a non-outcome",
@@ -33,7 +32,6 @@ export const DEDUPEDAUTHFETCH_BASELINE: Record<string, number> = {
 export const JSONPARSE_BASELINE: Record<string, number> = {
   "app/dashboard/hooks/deleteSessionResponse.ts": 1,
   "app/health-check/page.tsx": 1,
-  "components/landing/StatsBand.tsx": 2,
   "contexts/AuthContext.tsx": 2,
 };
 

src/Web/autopilot-monitor-web/lib/__tests__/platformStats.test.ts

@@ -0,0 +1,188 @@
+import { afterEach, beforeEach, describe, expect, it, vi, type MockInstance } from "vitest";
+import {
+  fetchLivePlatformStats,
+  loadPlatformStatsSnapshot,
+  resolvePlatformStatsManifestUrl,
+  toStatItems,
+} from "../platformStats";
+
+const CONTAINER = "https://stats.example.test/publicstats";
+const MANIFEST_URL = `${CONTAINER}/platform-stats.json`;
+const PAYLOAD_URL = `${CONTAINER}/platform-stats.2026-10-02T140005Z.json`;
+
+/** What the backend publishes (MaintenanceService.TryPublishPlatformStatsJsonAsync). */
+const MANIFEST = { latest: "platform-stats.2026-10-02T140005Z.json", generatedAtUtc: "2026-10-02T14:00:05.1234567Z" };
+const PAYLOAD = {
+  totalEnrollments: 12481,
+  totalUsers: 310,
+  totalTenants: 92,
+  totalSignedUpTenants: 87,
+  uniqueDeviceModels: 214,
+  totalEventsProcessed: 8341206,
+  successfulEnrollments: 11020,
+  issuesDetected: 1847,
+  lastFullCompute: "2026-10-02T14:00:03.1234567Z",
+  lastUpdated: "2026-10-02T14:00:03.1234567Z",
+};
+
+const BAND = [
+  { label: "enrollments monitored", value: "12,481" },
+  { label: "issues detected", value: "1,847" },
+  { label: "organisations", value: "87" },
+  { label: "device models", value: "214" },
+  { label: "events processed", value: "8.3M" },
+];
+
+function json(body: unknown, status = 200): Response {
+  return new Response(JSON.stringify(body), { status, headers: { "Content-Type": "application/json" } });
+}
+
+/** Answers by URL; anything not listed is a 404. */
+function serve(routes: Record<string, () => Response>) {
+  const fetchMock = vi.fn<(input: string, init?: RequestInit) => Promise<Response>>(async input =>
+    routes[input]?.() ?? new Response("not found", { status: 404 }));
+  vi.stubGlobal("fetch", fetchMock);
+  return fetchMock;
+}
+
+const BOTH_FILES = { [MANIFEST_URL]: () => json(MANIFEST), [PAYLOAD_URL]: () => json(PAYLOAD) };
+
+afterEach(() => {
+  vi.unstubAllGlobals();
+  vi.restoreAllMocks();
+});
+
+describe("resolvePlatformStatsManifestUrl", () => {
+  it("falls back to the same-origin manifest without a configured URL", () => {
+    expect([undefined, "", "  "].map(resolvePlatformStatsManifestUrl)).toEqual(Array(3).fill("/platform-stats.json"));
+  });
+
+  it("appends the manifest name to a container URL, with or without a trailing slash", () => {
+    expect(resolvePlatformStatsManifestUrl(CONTAINER)).toBe(MANIFEST_URL);
+    expect(resolvePlatformStatsManifestUrl(`${CONTAINER}/`)).toBe(MANIFEST_URL);
+  });
+
+  it("keeps a URL that already names a JSON file", () => {
+    expect(resolvePlatformStatsManifestUrl(MANIFEST_URL)).toBe(MANIFEST_URL);
+    expect(resolvePlatformStatsManifestUrl(`${CONTAINER}/custom.JSON`)).toBe(`${CONTAINER}/custom.JSON`);
+  });
+
+  it("keeps query and hash behind the appended manifest name", () => {
+    expect(resolvePlatformStatsManifestUrl(`${CONTAINER}?v=1#x`)).toBe(`${MANIFEST_URL}?v=1#x`);
+  });
+});
+
+describe("toStatItems", () => {
+  it("maps the band's figures in display order", () => {
+    expect(toStatItems(PAYLOAD)).toEqual(BAND);
+  });
+
+  it("leaves out figures that are missing, zero, negative or not a finite number", () => {
+    const payload = {
+      totalEnrollments: 0,
+      issuesDetected: -5,
+      totalSignedUpTenants: Number.POSITIVE_INFINITY,
+      uniqueDeviceModels: "214" as unknown as number,
+      totalEventsProcessed: 999_999,
+    };
+    expect(toStatItems(payload)).toEqual([{ label: "events processed", value: "999,999" }]);
+    expect(toStatItems({})).toEqual([]);
+  });
+});
+
+describe("fetchLivePlatformStats", () => {
+  it("revalidates the manifest and takes the immutable file it names from the browser cache", async () => {
+    const fetchMock = serve(BOTH_FILES);
+
+    expect(await fetchLivePlatformStats(MANIFEST_URL)).toEqual(PAYLOAD);
+    expect(fetchMock.mock.calls).toEqual([
+      [MANIFEST_URL, { cache: "no-cache" }],
+      [PAYLOAD_URL, { cache: "default" }],
+    ]);
+  });
+
+  it("resolves the versioned file against the manifest as served, after redirects", async () => {
+    const redirected = json(MANIFEST);
+    Object.defineProperty(redirected, "url", { value: "https://stats.example.test/v2/platform-stats.json" });
+    const fetchMock = serve({
+      [MANIFEST_URL]: () => redirected,
+      "https://stats.example.test/v2/platform-stats.2026-10-02T140005Z.json": () => json(PAYLOAD),
+    });
+
+    expect(await fetchLivePlatformStats(MANIFEST_URL)).toEqual(PAYLOAD);
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+  });
+
+  const failures: [string, Record<string, () => Response>][] = [
+    ["the manifest is missing", { [PAYLOAD_URL]: () => json(PAYLOAD) }],
+    ["the manifest names no file", { [MANIFEST_URL]: () => json({ generatedAtUtc: MANIFEST.generatedAtUtc }) }],
+    ["the manifest is not JSON", { [MANIFEST_URL]: () => new Response("<html></html>") }],
+    ["the manifest names a file on another origin", { [MANIFEST_URL]: () => json({ latest: "https://elsewhere.example.test/stats.json" }) }],
+    ["the versioned file is missing", { [MANIFEST_URL]: () => json(MANIFEST) }],
+    ["the versioned file holds no object", { [MANIFEST_URL]: () => json(MANIFEST), [PAYLOAD_URL]: () => json(42) }],
+  ];
+  for (const [name, routes] of failures) {
+    it(`returns null when ${name}`, async () => {
+      serve(routes);
+      expect(await fetchLivePlatformStats(MANIFEST_URL)).toBeNull();
+    });
+  }
+
+  it("returns null when the network fails", async () => {
+    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(new TypeError("Failed to fetch")));
+    expect(await fetchLivePlatformStats(MANIFEST_URL)).toBeNull();
+  });
+});
+
+describe("loadPlatformStatsSnapshot", () => {
+  let log: MockInstance<typeof console.log>;
+  let warn: MockInstance<typeof console.warn>;
+  beforeEach(() => {
+    log = vi.spyOn(console, "log").mockImplementation(() => undefined);
+    warn = vi.spyOn(console, "warn").mockImplementation(() => undefined);
+  });
+
+  it("bakes nothing and sends no request without an absolute URL (local and CI builds)", async () => {
+    const fetchMock = serve(BOTH_FILES);
+
+    expect(await loadPlatformStatsSnapshot("/platform-stats.json")).toBeNull();
+    expect(fetchMock).not.toHaveBeenCalled();
+    expect(warn).not.toHaveBeenCalled();
+  });
+
+  it("returns the band's items and the stats timestamp, read past Next's fetch cache within a deadline", async () => {
+    const fetchMock = serve(BOTH_FILES);
+
+    expect(await loadPlatformStatsSnapshot(MANIFEST_URL)).toEqual({ items: BAND, asOf: PAYLOAD.lastUpdated });
+    const inits = fetchMock.mock.calls.map(([, init]) => init);
+    expect(inits).toHaveLength(2);
+    for (const init of inits) {
+      expect(init?.cache).toBe("no-store");
+      expect(init?.signal).toBeInstanceOf(AbortSignal);
+    }
+    expect(inits[0]?.signal).toBe(inits[1]?.signal);
+    expect(log).toHaveBeenCalledWith(expect.stringContaining(`from ${MANIFEST.latest} (as of ${PAYLOAD.lastUpdated})`));
+  });
+
+  it("fails soft with the reason in the build log when the blob does not answer", async () => {
+    serve({ [MANIFEST_URL]: () => new Response("unavailable", { status: 503 }) });
+
+    expect(await loadPlatformStatsSnapshot(MANIFEST_URL)).toBeNull();
+    expect(warn).toHaveBeenCalledWith(expect.stringContaining("HTTP 503"));
+  });
+
+  it("names the network cause behind Node's generic fetch failure", async () => {
+    const failure = new TypeError("fetch failed", { cause: new Error("getaddrinfo ENOTFOUND stats.example.test") });
+    vi.stubGlobal("fetch", vi.fn().mockRejectedValue(failure));
+
+    expect(await loadPlatformStatsSnapshot(MANIFEST_URL)).toBeNull();
+    expect(warn).toHaveBeenCalledWith(expect.stringContaining("fetch failed (getaddrinfo ENOTFOUND stats.example.test)"));
+  });
+
+  it("bakes nothing when the file holds no positive figure", async () => {
+    serve({ [MANIFEST_URL]: () => json(MANIFEST), [PAYLOAD_URL]: () => json({ ...PAYLOAD, totalEnrollments: 0, issuesDetected: 0, totalSignedUpTenants: 0, uniqueDeviceModels: 0, totalEventsProcessed: 0 }) });
+
+    expect(await loadPlatformStatsSnapshot(MANIFEST_URL)).toBeNull();
+    expect(warn).toHaveBeenCalledWith(expect.stringContaining("no positive figure"));
+  });
+});

src/Web/autopilot-monitor-web/lib/__tests__/scriptExecutions.test.ts

@@ -1201,3 +1201,81 @@ describe("isOnOffsetGrid", () => {
     expect(isOnOffsetGrid(0)).toBe(false);
   });
 });
+
+describe("reduceScriptEvents — correction from IME's saved result (D-316)", () => {
+  const POLICY = "d94468af-6ebe-4e94-9901-2a62d33ea6c1";
+  const OWN = "=== Autopilot Monitor Bootstrap Started =====\nBootstrap script version: v2.5\nInstaller finished (exit code 0).";
+  const FOREIGN = "VERBOSE: === Sample Suite Detection Started ===\nWARNING: === DETECTION FAILED ===";
+  const correction = (data: Record<string, unknown>, at = 60): ScriptInputEvent => ({
+    timestamp: ts(at),
+    eventType: "script_output_reconciliation",
+    data: { policyId: POLICY, scriptType: "platform", ...data },
+  });
+
+  it("a foreign end block is replaced: the script's own output, no exit code, Success", () => {
+    const items = reduceScriptEvents([
+      finalEvent({ eventType: "script_failed", data: { policyId: POLICY, scriptType: "platform", runId: "r1", result: "Success", exitCode: "1", stdout: FOREIGN } }),
+      correction({ runId: "r1", outcome: "foreign", result: "Success", stdout: OWN, stderr: "", previousExitCode: "1" }),
+    ]);
+    expect(items).toHaveLength(1);
+    expect(items[0].state).toBe("Success");
+    expect(items[0].exitCode).toBeUndefined();
+    expect(items[0].stdout).toBe(OWN);
+    expect(items[0].stdout).not.toContain("Detection");
+    expect(items[0].outputCorrection).toBe("foreign");
+    expect(items[0].bootstrapVersion).toBe("2.5");
+  });
+
+  it("an incomplete output is completed and the exit code stands", () => {
+    const items = reduceScriptEvents([
+      finalEvent({ data: { policyId: POLICY, scriptType: "platform", runId: "r2", result: "Success", exitCode: "0" } }),
+      correction({ runId: "r2", outcome: "repaired", result: "Success", stdout: OWN, stderr: "" }),
+    ]);
+    expect(items[0].exitCode).toBe(0);
+    expect(items[0].stdout).toBe(OWN);
+    expect(items[0].outputCorrection).toBe("repaired");
+  });
+
+  it("a stdout split into stderr is mended: the empty stderr clears the failure", () => {
+    const items = reduceScriptEvents([
+      finalEvent({ eventType: "script_failed", data: { policyId: POLICY, scriptType: "platform", runId: "r3", result: "Success", exitCode: "0", stdout: "Copying files", stderr: "0 errors\nDone, error =" } }),
+      correction({ runId: "r3", outcome: "repaired", result: "Success", stdout: "Copying files, error = 0 errors\nDone", stderr: "" }),
+    ]);
+    expect(items[0].state).toBe("Success");
+    expect(items[0].stderr).toBeUndefined();
+    expect(items[0].stdout).toBe("Copying files, error = 0 errors\nDone");
+  });
+
+  it("a correction only applies to the run it names", () => {
+    const items = reduceScriptEvents([
+      finalEvent({ eventType: "script_failed", data: { policyId: POLICY, scriptType: "platform", runId: "r4", result: "Success", exitCode: "1", stdout: FOREIGN } }),
+      correction({ runId: "another-run", outcome: "foreign", result: "Success", stdout: OWN, stderr: "" }),
+    ]);
+    expect(items[0].state).toBe("Failed");
+    expect(items[0].exitCode).toBe(1);
+    expect(items[0].outputCorrection).toBeUndefined();
+  });
+
+  it("a correction without a stdout key keeps the emitted stdout", () => {
+    const items = reduceScriptEvents([
+      finalEvent({ eventType: "script_failed", data: { policyId: POLICY, scriptType: "platform", runId: "r5", result: "Failed", exitCode: "1", stdout: "partial" } }),
+      correction({ runId: "r5", outcome: "repaired", result: "Failed", stderr: "Access denied" }),
+    ]);
+    expect(items[0].stdout).toBe("partial");
+    expect(items[0].stderr).toBe("Access denied");
+    expect(items[0].state).toBe("Failed");
+  });
+
+  it("two runs of the same script never surface the corrected run's foreign output", () => {
+    const items = reduceScriptEvents([
+      finalEvent({ ts: 0, data: { policyId: POLICY, scriptType: "platform", runId: "old", result: "Success", exitCode: "0", runContext: "System", stdout: OWN } }),
+      finalEvent({ ts: 30, eventType: "script_failed", data: { policyId: POLICY, scriptType: "platform", runId: "r6", result: "Success", exitCode: "1", runContext: "System", stdout: FOREIGN } }),
+      correction({ runId: "r6", outcome: "foreign", result: "Success", stdout: OWN, stderr: "" }),
+    ]);
+    expect(items).toHaveLength(1);
+    expect(items[0].stdout).toBe(OWN);
+    expect(items[0].stdout).not.toContain("Detection");
+    expect(items[0].state).toBe("Success");
+    expect(items[0].exitCode === 1).toBe(false);
+  });
+});

src/Web/autopilot-monitor-web/lib/__tests__/standby.test.ts

@@ -95,6 +95,19 @@ describe("enrollmentWindowOf", () => {
     expect(w).toEqual({ startMs: Date.parse("2026-09-09T06:32:46Z"), endMs: Date.parse("2026-09-09T06:40:00Z") });
   });
 
+  it("ignores update, servicing and update-page rows backfilled from before the agent started", () => {
+    // D-315: the update watchers deliver rows with their event-log time up to 60 min before the agent;
+    // so does the update page telemetry on an agent's first run.
+    const w = enrollmentWindowOf([
+      activity(1, "2026-10-03T08:51:58Z", "windows_update_started", "WindowsUpdateWatcher"),
+      activity(2, "2026-10-03T08:52:37Z", "windows_update_servicing", "ServicingWatcher"),
+      activity(3, "2026-10-03T08:53:10Z", "oobe_update_page", "ShellCoreTracker"),
+      activity(4, "2026-10-03T08:56:46Z", "ime_agent_version", "ImeLogTracker"),
+      activity(5, "2026-10-03T10:08:09Z", "enrollment_complete", "DecisionEngine"),
+    ]);
+    expect(w).toEqual({ startMs: Date.parse("2026-10-03T08:56:46Z"), endMs: Date.parse("2026-10-03T10:08:09Z") });
+  });
+
   it("is null without activity events", () => {
     expect(enrollmentWindowOf([activity(1, "2026-09-09T06:00:00Z", "system_clock_changed", "SystemTimelineWatcher")])).toBeNull();
     expect(enrollmentWindowOf([])).toBeNull();

src/Web/autopilot-monitor-web/lib/platformStats.ts

@@ -0,0 +1,180 @@
+import type { PlatformStats } from "@/utils/wire-types.generated";
+
+/**
+ * The landing page's platform stats. A public blob container holds a manifest
+ * (`platform-stats.json`, rewritten by the backend maintenance run every 2 hours) that names the
+ * versioned file with the numbers (`latest`, relative to the manifest).
+ *
+ * Read twice: once by `next build`, which bakes the numbers of that moment into the static HTML
+ * (crawlers and LLM fetchers run no JS and would otherwise see only a skeleton), and again by
+ * every browser, which swaps in the live numbers (components/landing/StatsBand.tsx). Both reads
+ * share the URL, fetch and formatting rules here.
+ */
+
+interface PlatformStatsManifest {
+  latest: string;
+  generatedAtUtc: string;
+}
+
+/**
+ * The versioned file. The backend writes it field by field under the names of the wire type
+ * PlatformStats; every field stays optional because the body is parsed, not trusted.
+ */
+export type PlatformStatsPayload = Partial<PlatformStats>;
+
+export interface StatItem {
+  label: string;
+  value: string;
+}
+
+/** The numbers baked into the static HTML at build time. */
+export interface PlatformStatsSnapshot {
+  items: StatItem[];
+  /** When the backend computed them (the payload's lastUpdated): page marker and build log. */
+  asOf: string | null;
+}
+
+export function resolvePlatformStatsManifestUrl(rawUrl?: string): string {
+  const trimmed = rawUrl?.trim();
+  if (!trimmed) {
+    return "/platform-stats.json";
+  }
+
+  const hashIndex = trimmed.indexOf("#");
+  const withoutHash = hashIndex >= 0 ? trimmed.slice(0, hashIndex) : trimmed;
+  const hash = hashIndex >= 0 ? trimmed.slice(hashIndex) : "";
+
+  const queryIndex = withoutHash.indexOf("?");
+  const basePath = queryIndex >= 0 ? withoutHash.slice(0, queryIndex) : withoutHash;
+  const query = queryIndex >= 0 ? withoutHash.slice(queryIndex) : "";
+
+  if (/\.json$/i.test(basePath)) {
+    return trimmed;
+  }
+
+  const normalizedBasePath = basePath.endsWith("/") ? basePath.slice(0, -1) : basePath;
+  const manifestPath = `${normalizedBasePath}/platform-stats.json`;
+  return `${manifestPath}${query}${hash}`;
+}
+
+export const PLATFORM_STATS_MANIFEST_URL =
+  resolvePlatformStatsManifestUrl(process.env.NEXT_PUBLIC_PLATFORM_STATS_MANIFEST_URL);
+
+/** Budget for both build-time requests together: a slow blob must not stall the deploy. */
+const BUILD_FETCH_TIMEOUT_MS = 10_000;
+
+/** 8,341,206 → "8.3M"; smaller values keep their grouped form. */
+function compact(n: number): string {
+  if (n >= 1_000_000) return `${(n / 1_000_000).toFixed(1)}M`;
+  return n.toLocaleString("en-US");
+}
+
+function grouped(n: number): string {
+  return n.toLocaleString("en-US");
+}
+
+/** The band's figures in display order. */
+const STAT_FIELDS: { field: keyof PlatformStats; label: string; format: (n: number) => string }[] = [
+  { field: "totalEnrollments", label: "enrollments monitored", format: grouped },
+  { field: "issuesDetected", label: "issues detected", format: grouped },
+  { field: "totalSignedUpTenants", label: "organisations", format: grouped },
+  { field: "uniqueDeviceModels", label: "device models", format: grouped },
+  { field: "totalEventsProcessed", label: "events processed", format: compact },
+];
+
+/**
+ * The band's items. Only finite positive numbers count: the values end up in the static HTML,
+ * and a zero means "not computed yet", not a figure to publish.
+ */
+export function toStatItems(payload: PlatformStatsPayload): StatItem[] {
+  return STAT_FIELDS.flatMap(({ field, label, format }) => {
+    const value = payload[field];
+    return typeof value === "number" && Number.isFinite(value) && value > 0
+      ? [{ label, value: format(value) }]
+      : [];
+  });
+}
+
+/** One read: the numbers and the versioned file they came from (named in the build log). */
+interface PlatformStatsRead {
+  payload: PlatformStatsPayload;
+  file: string;
+}
+
+/**
+ * Manifest, then the file it names. Throws with the reason; the callers decide what to report.
+ * Each hop takes its own request options: the manifest changes with every publish, a versioned
+ * file never does.
+ */
+async function readPlatformStats(
+  manifestUrl: string,
+  manifestInit: RequestInit,
+  payloadInit: RequestInit = manifestInit,
+): Promise<PlatformStatsRead> {
+  const manifestResponse = await fetch(manifestUrl, manifestInit);
+  if (!manifestResponse.ok) throw new Error(`${manifestUrl} answered HTTP ${manifestResponse.status}`);
+  const manifest = (await manifestResponse.json()) as Partial<PlatformStatsManifest> | null;
+  if (typeof manifest?.latest !== "string" || !manifest.latest) {
+    throw new Error(`${manifestUrl} names no versioned file`);
+  }
+
+  // Relative to the manifest as served (after redirects); a hand-built Response has no url.
+  const base = manifestResponse.url || manifestUrl;
+  const payloadUrl = new URL(manifest.latest, base);
+  if (payloadUrl.origin !== new URL(base).origin) {
+    throw new Error(`${manifestUrl} names a file on another origin`);
+  }
+
+  const payloadResponse = await fetch(payloadUrl.toString(), payloadInit);
+  if (!payloadResponse.ok) throw new Error(`${payloadUrl} answered HTTP ${payloadResponse.status}`);
+  const payload: unknown = await payloadResponse.json();
+  if (typeof payload !== "object" || payload === null) throw new Error(`${payloadUrl} holds no stats object`);
+  return { payload: payload as PlatformStatsPayload, file: manifest.latest };
+}
+
+/**
+ * The browser's read. The manifest is revalidated on every load; the versioned file it names
+ * comes from the browser cache once fetched: the backend writes a new name per publish and serves
+ * it immutable (MaintenanceService.PlatformStatsVersionedFileName).
+ */
+export async function fetchLivePlatformStats(
+  manifestUrl: string = PLATFORM_STATS_MANIFEST_URL,
+): Promise<PlatformStatsPayload | null> {
+  try {
+    return (await readPlatformStats(manifestUrl, { cache: "no-cache" }, { cache: "default" })).payload;
+  } catch {
+    // The band is decorative: a failed read only means no live numbers.
+    return null;
+  }
+}
+
+/**
+ * The build's read (app/page.tsx), once per `next build`. Only for an absolute URL: local and CI
+ * builds have none (the relative fallback exists only in a browser) and bake nothing.
+ * `no-store` keeps the read out of Next's fetch cache, which would otherwise hand the next build
+ * on the same machine the previous numbers; the page is `force-static`, so `no-store` stays
+ * legal in the static export. Fail-soft: without a snapshot the page ships the skeleton and
+ * browsers load the numbers live, as before; deploy-web.yml reports it as a warning.
+ */
+export async function loadPlatformStatsSnapshot(
+  manifestUrl: string = PLATFORM_STATS_MANIFEST_URL,
+): Promise<PlatformStatsSnapshot | null> {
+  if (!/^https?:\/\//i.test(manifestUrl)) return null;
+  try {
+    const { payload, file } = await readPlatformStats(manifestUrl, {
+      cache: "no-store",
+      signal: AbortSignal.timeout(BUILD_FETCH_TIMEOUT_MS),
+    });
+    const items = toStatItems(payload);
+    if (items.length === 0) throw new Error(`${file} holds no positive figure`);
+    const asOf = typeof payload.lastUpdated === "string" ? payload.lastUpdated : null;
+    console.log(`Platform stats baked into the landing page from ${file} (as of ${asOf ?? "unknown"}).`);
+    return { items, asOf };
+  } catch (err) {
+    // Node's fetch reports every network failure as "fetch failed" and keeps the reason in `cause`.
+    const cause = err instanceof Error && err.cause instanceof Error ? ` (${err.cause.message})` : "";
+    const reason = err instanceof Error ? `${err.message}${cause}` : String(err);
+    console.warn(`Platform stats not baked into the landing page; browsers still load them live. ${reason}`);
+    return null;
+  }
+}

src/Web/autopilot-monitor-web/lib/scriptExecutions.ts

@@ -36,8 +36,19 @@ interface ScriptEventData {
   sourceOffsetOrigin?: string;
   /** "true" when the line's own timestamp was rejected and the event was stamped from the clock. */
   derivedTimestamp?: string | boolean;
+  /** Identity of one platform-script run; a script_output_reconciliation names the run it corrects (agents from 2026-10 on). */
+  runId?: string;
+  /** On script_output_reconciliation: "foreign" (the run had another script's end block) or "repaired". */
+  outcome?: string;
 }
 
+/**
+ * A platform run corrected after the fact from IME's saved result (D-316). Its `runId` names the
+ * script_completed/script_failed it corrects; a present `stdout`/`stderr` key replaces the emitted
+ * value (empty clears it), `outcome` "foreign" makes the emitted exit code unverified.
+ */
+export const SCRIPT_OUTPUT_RECONCILIATION = "script_output_reconciliation";
+
 export interface ScriptItem {
   policyId: string;
   scriptType: string;        // "platform" | "remediation"
@@ -80,6 +91,12 @@ export interface ScriptItem {
   state: "Running" | "Success" | "Failed";
   timestamp: string;
   bootstrapVersion?: string | null;
+  /**
+   * Set when IME's saved result corrected the run (script_output_reconciliation): "foreign" — the
+   * log had given the run another script's end block, so the output shown is the script's own from
+   * IME and the exit code is unknown; "repaired" — the log had delivered the output incomplete.
+   */
+  outputCorrection?: "foreign" | "repaired";
   /**
    * Set by applyObservationEnd, never by the fold: the script was still running when the
    * session's observation ended. Terminal, neither a failure nor a success — the outcome was
@@ -198,6 +215,9 @@ export function partitionHistoricScriptEvents(events: ScriptInputEvent[]): Histo
 function dataCompleteness(item: ScriptItem): number {
   let score = 0;
   if (item.exitCode != null) score += 4; // exit code is the most important signal
+  // A run corrected from IME's saved result lost a foreign exit code, not data: it must not lose
+  // the merge against a sibling run for that.
+  if (item.outputCorrection === "foreign") score += 4;
   if (item.result) score += 2;
   if (item.complianceResult) score += 2;
   if (item.remediationStatus != null) score += 1;
@@ -224,6 +244,18 @@ export function toNumber(v: unknown): number | undefined {
   return undefined;
 }
 
+/**
+ * The value a correction publishes for `key`, or the emitted one: a present key replaces it (an
+ * empty string clears it), an absent key keeps it.
+ */
+function correctedText(correction: ScriptEventData | undefined, key: "stdout" | "stderr", emitted: unknown): string | undefined {
+  if (correction && typeof correction[key] === "string") {
+    const value = correction[key] as string;
+    return value.length > 0 ? value : undefined;
+  }
+  return typeof emitted === "string" ? emitted : undefined;
+}
+
 /** Map RemediationStatus enum to the human-readable label shown in the detail panel. */
 export function mapRemediationStatus(status?: number): string | null {
   switch (status) {
@@ -378,7 +410,14 @@ export function reduceScriptEvents(events: ScriptInputEvent[]): ScriptItem[] {
   // script_started events per (policyId, scriptType) in timestamp order — the start line a
   // final is paired with when its run duration is judged (see judgeDurationPair).
   const startsByPolicy = new Map<string, ScriptInputEvent[]>();
+  // IME's saved result corrects a platform run after the fact; the correction names the run.
+  const correctionsByRunId = new Map<string, ScriptEventData>();
   for (const evt of sorted) {
+    if (evt.eventType === SCRIPT_OUTPUT_RECONCILIATION) {
+      const c = evt.data as ScriptEventData | undefined;
+      if (c && typeof c.runId === "string" && c.runId.length > 0) correctionsByRunId.set(c.runId, c);
+      continue;
+    }
     if (evt.eventType !== "script_started") continue;
     const d = evt.data as ScriptEventData | undefined;
     const startPolicyId = d?.policyId ?? d?.policy_id;
@@ -402,7 +441,10 @@ export function reduceScriptEvents(events: ScriptInputEvent[]): ScriptItem[] {
     const key = `${dedupeId}-${scriptType}-${scriptPart ?? ""}`;
     if (policyId) policyIdsWithFinal.add(`${policyId}-${scriptType}`);
 
-    const exitCode = toNumber(d.exitCode ?? d.exit_code);
+    const correction = typeof d.runId === "string" ? correctionsByRunId.get(d.runId) : undefined;
+    const outputCorrection = correction ? (correction.outcome === "foreign" ? "foreign" : "repaired") : undefined;
+    // A foreign end block's exit code belongs to another script: unknown, not the emitted value.
+    const exitCode = outputCorrection === "foreign" ? undefined : toNumber(d.exitCode ?? d.exit_code);
 
     // Duration normalization — the wire field durationSeconds carries two different
     // semantics, named by durationBasis (see the ScriptItem field docs):
@@ -435,8 +477,9 @@ export function reduceScriptEvents(events: ScriptInputEvent[]): ScriptItem[] {
     const remediationStatus = toNumber(d.remediationStatus ?? d.remediation_status);
     const targetType = toNumber(d.targetType ?? d.target_type);
     const errorCode = toNumber(d.errorCode ?? d.error_code);
-    const stdout = typeof d.stdout === "string" ? d.stdout : undefined;
-    const stderr = typeof d.stderr === "string" ? d.stderr : undefined;
+    const stdout = correctedText(correction, "stdout", d.stdout);
+    const stderr = correctedText(correction, "stderr", d.stderr);
+    const result = (typeof correction?.result === "string" ? correction.result : undefined) ?? d.result;
     const hasStderr = !!stderr && stderr.trim().length > 0;
 
     // State derivation — rules in priority order (mirrors the agent's EmitScriptCompleted):
@@ -450,8 +493,10 @@ export function reduceScriptEvents(events: ScriptInputEvent[]): ScriptItem[] {
     //   3. Defensive: explicit script_failed eventType OR result === "Failed" → Failed.
     const isHealthComplianceReport = scriptType === "remediation"
       && (scriptPart === "detection" || scriptPart === "post-detection");
-    const isFailureSignal = evt.eventType === "script_failed"
-      || d.result === "Failed"
+    // A corrected run is judged on its corrected data: the agent chose script_failed from the
+    // emitted values the correction replaced.
+    const isFailureSignal = (!correction && evt.eventType === "script_failed")
+      || result === "Failed"
       || (!isHealthComplianceReport && (hasStderr || (exitCode != null && exitCode !== 0)));
 
     const candidate: ScriptItem = {
@@ -460,7 +505,7 @@ export function reduceScriptEvents(events: ScriptInputEvent[]): ScriptItem[] {
       scriptPart,
       runContext: d.runContext ?? d.run_context,
       exitCode,
-      result: d.result,
+      result,
       complianceResult: d.complianceResult ?? d.compliance_result,
       remediationStatus,
       targetType,
@@ -476,6 +521,7 @@ export function reduceScriptEvents(events: ScriptInputEvent[]): ScriptItem[] {
       timestamp: evt.timestamp,
       bootstrapVersion: scriptType === "platform" ? extractBootstrapVersion(stdout) : null,
       isIncomplete: false,
+      outputCorrection,
     };
 
     // Keep the most-complete entry, but merge the duration fields across both: the

src/Web/autopilot-monitor-web/lib/standby.ts

@@ -1,4 +1,8 @@
 import type { EnrollmentEvent } from "@/types";
+import { SHARED_MANIFEST } from "@/utils/shared-manifests.generated";
+
+/** Sources whose rows never set a session's start (backend `Constants.EventSources.SessionAnchorIneligible`). */
+const ANCHOR_INELIGIBLE_SOURCES: ReadonlySet<string> = new Set(SHARED_MANIFEST.sessionAnchorIneligibleSources);
 
 export interface StandbyWindow {
   startMs: number;
@@ -7,17 +11,18 @@ export interface StandbyWindow {
 
 /**
  * The enrollment window as the session page measures its duration: first activity event →
- * `enrollment_complete`, or the last activity event while no verdict exists. System-timeline
- * rows (clock steps, sleep episodes) are excluded — they are backfilled from the Windows event
- * log with timestamps up to 24 h before the agent started and would drag the start into
- * pre-enrollment idle time. Null when the session has no activity events.
+ * `enrollment_complete`, or the last activity event while no verdict exists. Backfilled
+ * environment rows (clock steps, sleep, update and servicing activity, the update page) are excluded, as in the
+ * backend's session anchor — they carry Windows event-log timestamps from before the agent
+ * started and would drag the start into pre-enrollment time. Null when the session has no
+ * activity events.
  */
 export function enrollmentWindowOf(events: EnrollmentEvent[]): StandbyWindow | null {
   let startMs = Number.POSITIVE_INFINITY;
   let lastMs = Number.NEGATIVE_INFINITY;
   let completeMs: number | null = null;
   for (const e of events) {
-    if (e.source === "SystemTimelineWatcher") continue;
+    if (ANCHOR_INELIGIBLE_SOURCES.has(e.source)) continue;
     const t = new Date(e.timestamp).getTime();
     if (!Number.isFinite(t)) continue;
     if (t < startMs) startMs = t;

src/Web/autopilot-monitor-web/scripts/generate-lastmod.js

@@ -18,7 +18,7 @@ const OUTPUT_FILE = path.join(WEB_ROOT, "utils/page-lastmod.generated.ts");
 // fails the build for any URL missing here. Documentation and the changelog
 // live on docs.autopilotmonitor.com (GitBook) and are not part of this site.
 const PAGE_MAP = {
-  "/": ["app/page.tsx"],
+  "/": ["app/page.tsx", "components/landing/LandingPage.tsx"],
   "/about": ["app/about/page.tsx", "app/about/faq.ts"],
   "/ai": ["app/ai/page.tsx", "components/ai/questions.ts"],
   "/get-started": ["app/get-started/page.tsx"],

src/Web/autopilot-monitor-web/utils/shared-manifests.generated.ts

@@ -503,6 +503,18 @@ export const SHARED_MANIFEST = {
     "ime",
     "realmjoin"
   ],
+  "sessionAnchorIneligibleSources": [
+    "SystemTimelineWatcher",
+    "WindowsUpdateWatcher",
+    "ServicingWatcher",
+    "ShellCoreTracker"
+  ],
+  "osUpdateOutcomes": [
+    "installed",
+    "failed",
+    "skipped",
+    "unknown"
+  ],
   "ruleSubmissionKinds": [
     "gather",
     "analyze"
@@ -895,6 +907,7 @@ export const SHARED_MANIFEST = {
     "remote_config_fetch_failed",
     "script_completed",
     "script_failed",
+    "script_output_reconciliation",
     "script_recurrence_summary",
     "script_started",
     "script_timeout_suspected",

src/Web/autopilot-monitor-web/utils/shared-manifests.json

@@ -499,6 +499,18 @@
     "ime",
     "realmjoin"
   ],
+  "sessionAnchorIneligibleSources": [
+    "SystemTimelineWatcher",
+    "WindowsUpdateWatcher",
+    "ServicingWatcher",
+    "ShellCoreTracker"
+  ],
+  "osUpdateOutcomes": [
+    "installed",
+    "failed",
+    "skipped",
+    "unknown"
+  ],
   "ruleSubmissionKinds": [
     "gather",
     "analyze"
@@ -891,6 +903,7 @@
     "remote_config_fetch_failed",
     "script_completed",
     "script_failed",
+    "script_output_reconciliation",
     "script_recurrence_summary",
     "script_started",
     "script_timeout_suspected",
@@ -14404,7 +14417,26 @@
               "name": "string"
             }
           },
-          "doc": "KB numbers of the packages Windows serviced in the interval (\"KB5129195\"), in order of first appearance; empty when no package named one."
+          "doc": "KB numbers of the packages that reached \"Installed\" in the interval (\"KB5129195\"), in order of first appearance; empty when none did or no package named one."
+        },
+        {
+          "name": "notInstalledKbs",
+          "type": {
+            "kind": "array",
+            "element": {
+              "kind": "primitive",
+              "name": "string"
+            }
+          },
+          "doc": "KB numbers of the packages Windows serviced in the interval without reaching \"Installed\" (for example only staged before a failed download)."
+        },
+        {
+          "name": "outcome",
+          "type": {
+            "kind": "primitive",
+            "name": "string"
+          },
+          "doc": "How the update ended — one of OsUpdateOutcomes; the latest outcome evidence in the interval decides."
         },
         {
           "name": "rebootCount",

src/Web/autopilot-monitor-web/utils/wire-types.generated.ts

@@ -3060,8 +3060,12 @@ export interface OsUpdateSpan {
   endUtc: string;
   /** In-window seconds of the interval. */
   seconds: number;
-  /** KB numbers of the packages Windows serviced in the interval ("KB5129195"), in order of first appearance; empty when no package named one. */
+  /** KB numbers of the packages that reached "Installed" in the interval ("KB5129195"), in order of first appearance; empty when none did or no package named one. */
   kbs: string[];
+  /** KB numbers of the packages Windows serviced in the interval without reaching "Installed" (for example only staged before a failed download). */
+  notInstalledKbs: string[];
+  /** How the update ended — one of OsUpdateOutcomes; the latest outcome evidence in the interval decides. */
+  outcome: string;
   /** Restarts that began inside the interval. */
   rebootCount: number;
 }