Incorporate supplied upstream frontier for diagnostic-test review

Retain the batch-start main frontier before integrating the independently reviewed documentation-test candidate. No publication or deployment.

Change-source: pulse-maintainer

docs/release-control/v6/internal/subsystems/api-contracts.md

@@ -1761,6 +1761,17 @@ payload shape change when the portal presents compact client rows.
     `frontend-modern/src/components/Settings/AvailabilitySettingsPanel.tsx`,
     `frontend-modern/src/components/Settings/availabilitySettingsModel.ts`,
     and `AvailabilityTargetSlot.tsx` own the browser transport shape.
+    The settings summary and status pills classify each target through
+    `getAvailabilityTargetHealth`. When the target's unified
+    `network-endpoint` resource is loaded, the Machines tab's
+    `getStandaloneResourceStatusIndicator` decides, so stale evidence and
+    unresolved identity count the same on both pages. Otherwise the target's
+    own status is read the way `availability_poller.go` derives the resource
+    status: aggregate and single-location failures are offline only once
+    consecutive failures reach the failure threshold (default 2), a missing
+    count is zero, and a never-checked target is pending. Settings and the
+    Machines availability tab therefore report the same counts in the same
+    words.
     Availability target probe-result and error notices may compose
     frontend-primitives' `CalloutCard` for shared settings callout chrome;
     API contracts own the target CRUD/test payload semantics and endpoint

docs/release-control/v6/internal/subsystems/frontend-primitives.md

@@ -7338,7 +7338,9 @@ successful evidence must render an amber `Stale` state with no green
 must not appear as a primary row in the Machines `Availability checks` tab;
 the distinct source-owned `network-endpoint` for that configured check must
 appear there regardless of whether its correlation state is `attached`,
-`standalone`, `ambiguous`, or `unresolved`.
+`standalone`, `ambiguous`, or `unresolved`. The tab's summary card owns the one
+"Manage checks" link; the checks table toolbar keeps only "Add service/device
+check".
 Operational navigation for those agentless endpoints belongs to the
 frontend-primitives-owned Machines surface as a focused Availability checks tab
 rather than a new primary nav item. The page may show availability checks beside

docs/release-control/v6/internal/subsystems/unified-resources.md

@@ -3246,7 +3246,11 @@ as separate buckets in `standalonePageModel.ts`, include every source-owned
 `network-endpoint` regardless of correlation state, exclude matched machine or
 service projections from the check inventory by resource type, and let
 `AvailabilityChecksTable.tsx` render saved probe method, target, latest result,
-check age, failure count, and cadence from the canonical availability payload.
+24h uptime, check age, last healthy time and failure count from the canonical
+availability payload, with cadence restored only on the widest tables. Uptime
+comes from the shared availability history summary the fleet view reads and
+stays blank below 90 percent observed. The failure count reads "N in a row",
+with the offline threshold on hover, not an "N/M" fraction.
 Recent check timing and fuller failure context may stay in tooltip or drawer
 detail, but the table row must not duplicate the same probe protocol and
 result text across both identity and metric cells.