docs(CUST-WP-0054-T05): open Phase 5 stabilization window

Record kickoff baseline checks, 72h monitoring gates, and a reusable
phase5-stabilization-check.sh script for daily health snapshots.

docs/state-hub-railiance01-cutover-phase5-2026-07-06.md

@@ -0,0 +1,80 @@
+# T05 Phase 5 Evidence — Stabilization Window (2026-07-06)
+
+Workplan: `CUST-WP-0054-T05`  
+Parent runbook: `docs/state-hub-railiance01-cutover-plan.md`  
+`no_secret_material_recorded: true`
+
+## Window
+
+| Field | Value |
+| --- | --- |
+| Started | 2026-07-06 ~17:35 UTC |
+| Target close | 2026-07-09 17:35 UTC (72h) |
+| Owner | custodian |
+| Rollback | coulombcore `state-hub` Deployment + dumps retained ≥7 days |
+
+**Phase 5 status: in progress.**
+
+## Kickoff baseline (2026-07-06T17:41Z)
+
+| Check | Result | Evidence |
+| --- | --- | --- |
+| Hub `/state/health` | **pass** | `{"status":"ok","db":"connected"}` via `state-hub-primary` |
+| Row-count gate | **pass** | workstreams **640**, tasks **4002**, topics **14** (matches Phase 2 gate) |
+| railiance01 pod | **pass** | `state-hub-67f8b5d5d-9mmd5` Running, **0** restarts |
+| CNPG `state-hub-db` | **pass** | `Cluster in healthy state`, 1/1 |
+| coulombcore rollback | **pass** | `state-hub` replicas=**0** (not deleted) |
+| activity-core hub path | **pass** | in-cluster `http://state-hub.state-hub.svc.cluster.local:8000`; bridge **0** |
+| Consistency sweeps | **pass** | 6/6 recent events `exit_code=0`, `skipped_missing=0` (post-17:15 UTC) |
+| Sweep writeback host | **pass** | repos resolve `/home/tegwick/*` (Phase 4) |
+| Workstation tunnel | **pass** | `state-hub-primary` connected + LIVE → railiance01 |
+| Daily triage (post-cutover) | **pending** | last `daily_triage` 2026-07-06T05:20Z (pre-Phase-3); next cron 07:20 Europe/Berlin |
+| issue-core emission | **unchanged** | `issue-core-coulombcore` tunnel connected; null-sink audit mode (Wave 4) |
+
+Kickoff sweep (`source=phase5-kickoff`): **exit_code=0**, 10 repos processed, 0 missing.
+
+## Monitoring
+
+Run daily (or after incidents):
+
+```bash
+~/the-custodian/tools/phase5-stabilization-check.sh
+```
+
+Sweep history (24h):
+
+```bash
+cd ~/state-hub
+uv run python scripts/compare_consistency_sweep_parallel.py --since-hours 24
+```
+
+## Exit gates (T05 done)
+
+From `docs/state-hub-railiance01-cutover-plan.md` verification checklist:
+
+- [x] `/state/summary` totals match pre-cutover (±0)
+- [ ] activity-core **daily triage** succeeds once post-cutover (watch 2026-07-07 07:20 CEST)
+- [x] activity-core **consistency sweeps** succeed without `fleet-state-hub-coulombcore`
+- [x] Workstation `:8000` serves railiance01 hub
+- [x] Writeback lands on railiance01 clone path
+- [x] coulombcore hub scaled to 0
+- [x] Cutover progress notes recorded (Phases 0–5)
+
+**Close Phase 5 / mark T05 done when:** 72h window passes with no data-loss signals,
+sweeps stay `exit_code=0` (lock_skipped acceptable), one post-cutover daily triage
+succeeds, and operator approves coulombcore hub teardown window.
+
+## Known watch items
+
+1. **Sweep budget** — 300s processes ~8–10 dirty repos per tick; expect gradual
+   reconciliation across 15m cron cycles (not a blocker).
+2. **Image tag** — production uses hand-imported `main-phase4-sweep`; promote via
+   Forgejo CI before next unrelated deploy.
+3. **Stale tunnel** — `state-hub-coulombcore` shows `[STALE]`; safe to retire after
+   stabilization if unused.
+4. **issue-core** — still coulombcore-chained; tracked under Wave 4 / T06, not T05.
+
+## References
+
+- Phase 4: `docs/state-hub-railiance01-cutover-phase4-2026-07-06.md`
+- Sweep runbook: `state-hub/docs/consistency-sweep-runbook.md`