Preserve fresh rolling-window metric authority

Keep in-memory observations authoritative over duplicate persisted history, add direct provider and cache reset coverage, and register the rolling-window proof files with canonical governance.\n\nChange-source: pulse-maintainer

docs/release-control/v6/internal/subsystems/monitoring.md

@@ -437,10 +437,13 @@ identity and durable history as charts. `internal/monitoring/metric_window_provi
 resolves the unified resource metrics target, reads the fresh in-memory tail,
 and falls back to the SQLite metrics store when that tail lacks the requested
 coverage. Persistent fallbacks are briefly cached to bound restart-time query
-load, merged by timestamp, and returned as observations only; alert policy owns
-averaging, readiness, hysteresis, and lifecycle decisions. Missing target,
-query failure, shallow history, or gapped history must remain unknown at the
-alerts boundary rather than being replaced by a synthetic healthy value.
+load, merged by timestamp, and returned as observations only. When the durable
+series and fresh in-memory tail contain the same timestamp, the in-memory value
+is authoritative so an older persisted or rolled-up value cannot replace the
+latest observation. Alert policy owns averaging, readiness, hysteresis, and
+lifecycle decisions. Missing target, query failure, shallow history, or gapped
+history must remain unknown at the alerts boundary rather than being replaced
+by a synthetic healthy value.
 
 Monitoring ingest keeps mock mode hermetic. The unified read path already
 substitutes the mock snapshot wholesale, so anything that runs after that

docs/release-control/v6/internal/subsystems/registry.json

@@ -2334,7 +2334,8 @@
               "internal/alerts/unified_eval_parity_test.go",
               "internal/alerts/unified_eval_test.go",
               "internal/alerts/unified_incident_confirmation_test.go",
-              "internal/alerts/unified_incidents_test.go"
+              "internal/alerts/unified_incidents_test.go",
+              "internal/alerts/windowed_metric_test.go"
             ]
           },
           {
@@ -2540,6 +2541,7 @@
               "internal/alerts/callback_config_coverage_test.go",
               "internal/alerts/canonical_override_migration_test.go",
               "internal/alerts/canonical_stateful_test.go",
+              "internal/alerts/config/evaluation_windows_test.go",
               "internal/alerts/config_validation_test.go",
               "internal/alerts/eventlog/eventlog_snapshot_test.go",
               "internal/alerts/external_probe_test.go",
@@ -2564,6 +2566,7 @@
               "internal/alerts/threshold_resolution_shared_test.go",
               "internal/alerts/unified_incident_confirmation_test.go",
               "internal/alerts/update_alerts_test.go",
+              "internal/alerts/windowed_metric_test.go",
               "internal/monitoring/deadman_test.go",
               "internal/monitoring/monitor_alert_override_migration_test.go"
             ]
@@ -5715,6 +5718,7 @@
             "allow_same_subsystem_tests": false,
             "test_prefixes": [],
             "exact_files": [
+              "internal/monitoring/metric_window_provider_test.go",
               "internal/monitoring/metrics_history_concurrency_test.go",
               "internal/monitoring/metrics_history_memory_regression_test.go",
               "internal/monitoring/metrics_history_test.go",
@@ -6055,6 +6059,7 @@
               "internal/monitoring/issue1595_collection_trust_test.go",
               "internal/monitoring/issue1613_contract_test.go",
               "internal/monitoring/issue1638_dns_cache_test.go",
+              "internal/monitoring/metric_window_provider_test.go",
               "internal/monitoring/monitor_additional_test.go",
               "internal/monitoring/monitor_alert_intent_test.go",
               "internal/monitoring/monitor_alert_override_migration_test.go",

internal/monitoring/metric_window_provider.go

@@ -58,7 +58,9 @@ func (m *Monitor) metricWindowPoints(request alerts.MetricWindowRequest) ([]aler
 	points := m.inMemoryMetricWindow(resourceType, resourceID, metric, duration)
 	if metricWindowCoverage(points) < duration*8/10 {
 		stored := m.persistentMetricWindow(resourceType, resourceID, metric, request.Start, request.End)
-		points = mergeMetricWindowPoints(points, stored, request.Start, request.End)
+		// Append the fresh in-memory tail last so it remains authoritative when
+		// SQLite contains an older value at the same timestamp.
+		points = mergeMetricWindowPoints(stored, points, request.Start, request.End)
 	}
 
 	result := make([]alerts.MetricWindowPoint, 0, len(points))

internal/monitoring/metric_window_provider_test.go

@@ -0,0 +1,65 @@
+package monitoring
+
+import (
+	"testing"
+	"time"
+
+	"github.com/rcourtman/pulse-go-rewrite/internal/alerts"
+)
+
+func TestMetricWindowPointsUsesInMemoryMetricAlias(t *testing.T) {
+	now := time.Now().UTC()
+	history := NewMetricsHistory(32, time.Hour)
+	history.AddGuestMetric("vm-1", "netin", 12, now.Add(-4*time.Minute))
+	history.AddGuestMetric("vm-1", "netin", 18, now.Add(-2*time.Minute))
+	monitor := &Monitor{metricsHistory: history}
+
+	points, err := monitor.metricWindowPoints(alerts.MetricWindowRequest{
+		ResourceID:   "vm-1",
+		ResourceType: "vm",
+		Metric:       "networkIn",
+		Start:        now.Add(-5 * time.Minute),
+		End:          now,
+	})
+	if err != nil {
+		t.Fatalf("metricWindowPoints returned error: %v", err)
+	}
+	if len(points) != 2 || points[0].Value != 12 || points[1].Value != 18 {
+		t.Fatalf("metricWindowPoints = %+v, want canonical netin history", points)
+	}
+}
+
+func TestMetricWindowMergePrefersFreshInMemoryDuplicate(t *testing.T) {
+	now := time.Now().UTC()
+	stored := []MetricPoint{
+		{Timestamp: now.Add(-4 * time.Minute), Value: 40},
+		{Timestamp: now.Add(-2 * time.Minute), Value: 99},
+	}
+	inMemory := []MetricPoint{
+		{Timestamp: now.Add(-2 * time.Minute), Value: 55},
+		{Timestamp: now.Add(-time.Minute), Value: 60},
+	}
+
+	got := mergeMetricWindowPoints(stored, inMemory, now.Add(-5*time.Minute), now)
+	if len(got) != 3 {
+		t.Fatalf("mergeMetricWindowPoints returned %d points, want 3: %+v", len(got), got)
+	}
+	if got[1].Value != 55 {
+		t.Fatalf("duplicate timestamp value = %.1f, want fresh in-memory value 55", got[1].Value)
+	}
+}
+
+func TestMetricsHistoryResetClearsMetricWindowCache(t *testing.T) {
+	history := NewMetricsHistory(32, time.Hour)
+	history.metricWindowCache = map[string]metricWindowCacheEntry{
+		"vm\x00vm-1\x00cpu\x00300": {
+			points:    []alerts.MetricWindowPoint{{Timestamp: time.Now().UTC(), Value: 42}},
+			expiresAt: time.Now().Add(time.Minute),
+		},
+	}
+
+	history.Reset()
+	if history.metricWindowCache != nil {
+		t.Fatalf("metric window cache survived reset: %+v", history.metricWindowCache)
+	}
+}

scripts/release_control/canonical_completion_guard_test.py

@@ -304,6 +304,7 @@ class CanonicalCompletionGuardTest(unittest.TestCase):
                         "internal/monitoring/issue1595_collection_trust_test.go",
                         "internal/monitoring/issue1613_contract_test.go",
                         "internal/monitoring/issue1638_dns_cache_test.go",
+                        "internal/monitoring/metric_window_provider_test.go",
                         "internal/monitoring/monitor_additional_test.go",
                         "internal/monitoring/monitor_alert_intent_test.go",
                         "internal/monitoring/monitor_alert_override_migration_test.go",

scripts/release_control/registry_audit_test.py

@@ -87,10 +87,13 @@ class RegistryAuditTest(unittest.TestCase):
             },
             ("alerts", "canonical-alert-runtime"): {
                 "internal/alerts/intent_policy_test.go",
+                "internal/alerts/windowed_metric_test.go",
             },
             ("alerts", "alerts-runtime-support"): {
                 "internal/alerts/canonical_override_migration_test.go",
+                "internal/alerts/config/evaluation_windows_test.go",
                 "internal/alerts/intent_policy_test.go",
+                "internal/alerts/windowed_metric_test.go",
                 "internal/monitoring/monitor_alert_override_migration_test.go",
             },
             ("api-contracts", "alert-intent-policy-api"): {
@@ -126,9 +129,13 @@ class RegistryAuditTest(unittest.TestCase):
             ("monitoring", "monitoring-runtime"): {
                 "internal/monitoring/availability_udp_test.go",
                 "internal/monitoring/issue1595_collection_trust_test.go",
+                "internal/monitoring/metric_window_provider_test.go",
                 "internal/monitoring/monitor_alert_intent_test.go",
                 "internal/monitoring/monitor_alert_override_migration_test.go",
             },
+            ("monitoring", "metrics-history-runtime"): {
+                "internal/monitoring/metric_window_provider_test.go",
+            },
             ("monitoring", "agent-fleet-diagnostics-runtime"): {
                 "internal/api/agent_fleet_doctor_test.go",
                 "internal/api/connections_aggregator_test.go",

scripts/release_control/subsystem_lookup_test.py

@@ -4230,6 +4230,7 @@ class SubsystemLookupTest(unittest.TestCase):
         self.assertEqual(
             match["verification_requirement"]["exact_files"],
             [
+                "internal/monitoring/metric_window_provider_test.go",
                 "internal/monitoring/metrics_history_concurrency_test.go",
                 "internal/monitoring/metrics_history_memory_regression_test.go",
                 "internal/monitoring/metrics_history_test.go",