docs(08-03): complete observability verification plan

Tasks completed: 3/3
- Deploy TaskPlanner with ServiceMonitor and verify Prometheus scraping
- Verify critical alert rules exist
- Human verification checkpoint (all OBS requirements verified)

Deviation: Fixed Loki datasource conflict (isDefault collision with Prometheus)

SUMMARY: .planning/phases/08-observability-stack/08-03-SUMMARY.md

.planning/STATE.md

@@ -5,16 +5,16 @@
 See: .planning/PROJECT.md (updated 2026-02-01)
 
 **Core value:** Capture and find anything from any device — especially laptop. If cross-device capture with images doesn't work, nothing else matters.
-**Current focus:** v2.0 Production Operations — Phase 8 (Observability Stack)
+**Current focus:** v2.0 Production Operations — Phase 8 (Observability Stack) COMPLETE
 
 ## Current Position
 
-Phase: 8 of 9 (Observability Stack) - IN PROGRESS
+Phase: 8 of 9 (Observability Stack) - COMPLETE
-Plan: 2 of 3 in current phase - COMPLETE
+Plan: 3 of 3 in current phase - COMPLETE
-Status: In progress
+Status: Phase complete
-Last activity: 2026-02-03 — Completed 08-02-PLAN.md (Promtail to Alloy Migration)
+Last activity: 2026-02-03 — Completed 08-03-PLAN.md (Observability Verification)
 
-Progress: [██████████████████████░░░░░░░░] 88% (22/25 plans complete)
+Progress: [████████████████████████░░░░░░] 92% (23/25 plans complete)
 
 ## Performance Metrics
 
@@ -26,8 +26,8 @@ Progress: [██████████████████████░
 - Requirements satisfied: 31/31
 
 **v2.0 Progress:**
-- Plans completed: 4/7
+- Plans completed: 5/7
-- Total execution time: 38 min
+- Total execution time: 44 min
 
 **By Phase (v1.0):**
 
@@ -45,7 +45,7 @@ Progress: [██████████████████████░
 | Phase | Plans | Total | Avg/Plan |
 |-------|-------|-------|----------|
 | 07-gitops-foundation | 2/2 | 26 min | 13 min |
-| 08-observability-stack | 2/3 | 12 min | 6 min |
+| 08-observability-stack | 3/3 | 18 min | 6 min |
 
 ## Accumulated Context
 
@@ -77,6 +77,10 @@ For v2.0, key decisions from research:
 - Match Promtail labels for Loki query compatibility
 - Control-plane node tolerations required for full DaemonSet coverage
 
+**From Phase 8-03:**
+- Loki datasource isDefault must be false when Prometheus is default datasource
+- ServiceMonitor needs `release: kube-prometheus-stack` label for discovery
+
 ### Pending Todos
 
 - Deploy Gitea Actions runner for automatic CI builds
@@ -88,10 +92,10 @@ For v2.0, key decisions from research:
 
 ## Session Continuity
 
-Last session: 2026-02-03 21:12 UTC
+Last session: 2026-02-03 21:44 UTC
-Stopped at: Completed 08-02-PLAN.md
+Stopped at: Completed 08-03-PLAN.md (Phase 8 complete)
 Resume file: None
 
 ---
 *State initialized: 2026-01-29*
-*Last updated: 2026-02-03 — Completed 08-02-PLAN.md (Promtail to Alloy Migration)*
+*Last updated: 2026-02-03 — Completed 08-03-PLAN.md (Observability Verification)*

.planning/phases/08-observability-stack/08-03-SUMMARY.md

@@ -0,0 +1,126 @@
+---
+phase: 08-observability-stack
+plan: 03
+subsystem: infra
+tags: [prometheus, grafana, loki, alertmanager, servicemonitor, observability, kubernetes]
+
+# Dependency graph
+requires:
+  - phase: 08-01
+    provides: TaskPlanner /metrics endpoint and ServiceMonitor
+  - phase: 08-02
+    provides: Grafana Alloy for log collection
+provides:
+  - End-to-end verified observability stack
+  - Prometheus scraping TaskPlanner metrics
+  - Loki log queries verified in Grafana
+  - Alerting rules confirmed (KubePodCrashLooping)
+affects: [operations, future-monitoring, troubleshooting]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns: [datasource-conflict-resolution]
+
+key-files:
+  created: []
+  modified:
+    - loki-stack ConfigMap (isDefault fix)
+
+key-decisions:
+  - "Loki datasource isDefault must be false when Prometheus is default datasource"
+
+patterns-established:
+  - "Datasource conflict: Only one Grafana datasource can have isDefault: true"
+
+# Metrics
+duration: 6min
+completed: 2026-02-03
+---
+
+# Phase 8 Plan 03: Observability Verification Summary
+
+**End-to-end observability verified: Prometheus scraping TaskPlanner metrics, Loki log queries working, dashboards operational**
+
+## Performance
+
+- **Duration:** 6 min
+- **Started:** 2026-02-03T21:38:00Z (approximate)
+- **Completed:** 2026-02-03T21:44:08Z
+- **Tasks:** 3 (2 auto, 1 checkpoint)
+- **Files modified:** 1 (loki-stack ConfigMap patch)
+
+## Accomplishments
+
+- ServiceMonitor deployed and Prometheus scraping TaskPlanner /metrics endpoint
+- KubePodCrashLooping alert rule confirmed present in kube-prometheus-stack
+- Alertmanager running and responsive
+- Human verified: Grafana TLS working, dashboards showing metrics, Loki log queries returning TaskPlanner logs
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Deploy TaskPlanner with ServiceMonitor and verify Prometheus scraping** - `91f91a3` (fix: add release label for Prometheus discovery)
+2. **Task 2: Verify critical alert rules exist** - no code changes (verification only)
+3. **Task 3: Human verification checkpoint** - user verified
+
+**Plan metadata:** pending
+
+## Files Created/Modified
+
+- `loki-stack ConfigMap` (in-cluster) - Patched isDefault from true to false to resolve datasource conflict
+
+## Decisions Made
+
+- Added `release: kube-prometheus-stack` label to ServiceMonitor to match Prometheus Operator's serviceMonitorSelector
+- Patched Loki datasource isDefault to false to allow Prometheus as default (Grafana only supports one default)
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 1 - Bug] Fixed Loki datasource conflict causing Grafana crash**
+- **Found during:** Task 1 (verifying Grafana accessibility)
+- **Issue:** Both Prometheus and Loki datasources had `isDefault: true`, causing Grafana to crash with "multiple default datasources" error. User couldn't see any datasources.
+- **Fix:** Patched loki-stack ConfigMap to set `isDefault: false` for Loki datasource
+- **Command:** `kubectl patch configmap loki-stack-datasource -n monitoring --type merge -p '{"data":{"loki-stack-datasource.yaml":"...isDefault: false..."}}'`
+- **Verification:** Grafana restarted, both datasources now visible and queryable
+- **Committed in:** N/A (in-cluster configuration, not git-tracked)
+
+---
+
+**Total deviations:** 1 auto-fixed (1 bug)
+**Impact on plan:** Essential fix for Grafana usability. No scope creep.
+
+## Issues Encountered
+
+- ServiceMonitor initially not discovered by Prometheus - resolved by adding `release: kube-prometheus-stack` label to match selector
+- Grafana crashing on startup due to datasource conflict - resolved via ConfigMap patch
+
+## OBS Requirements Verified
+
+| Requirement | Description | Status |
+|-------------|-------------|--------|
+| OBS-01 | Prometheus collects cluster metrics | Verified |
+| OBS-02 | Grafana dashboards display cluster metrics | Verified |
+| OBS-03 | Loki stores application logs | Verified |
+| OBS-04 | Alloy collects and forwards logs | Verified |
+| OBS-05 | Grafana can query logs from Loki | Verified |
+| OBS-06 | Critical alerts configured (KubePodCrashLooping) | Verified |
+| OBS-07 | Grafana TLS via Traefik | Verified |
+| OBS-08 | TaskPlanner /metrics endpoint | Verified |
+
+## User Setup Required
+
+None - all configuration applied to cluster. No external service setup required.
+
+## Next Phase Readiness
+
+- Phase 8 (Observability Stack) complete
+- Ready for Phase 9 (Security Hardening) or ongoing operations
+- Observability foundation established for production monitoring
+
+---
+*Phase: 08-observability-stack*
+*Completed: 2026-02-03*