M26: harden clean observability acceptance

PROJECT_STATE.md

@@ -2594,3 +2594,20 @@ evidence yet."
   prior Starlette/httpx warning is confirmed absent in the rebuilt environment.
 - Exact next action: run complete clean acceptance, push all five milestone commits,
   create a verified live backup, redeploy and execute live browser acceptance.
+
+## M26 — clean acceptance hardening (2026-08-10)
+
+- The clean full-suite run exposed and fixed two observability regressions that targeted
+  runs against a stale image had missed: readiness now returns immediately with 503 only
+  on database failure and reaches the healthy 200 branch correctly; Prometheus outbox
+  series now use the documented label order.
+- All synthetic/operational and pending/delivering/succeeded/failed outbox combinations
+  are initialized to zero before persisted counts are applied. Fresh installs, restores
+  and demo resets therefore produce stable zero-valued metrics instead of misleading
+  `no data` panels and absent alert inputs.
+- Evidence from the final rebuilt isolated stack: complete backend **239 passed with zero
+  warnings**, ruff passed and mypy passed across 58 source files. Frontend TypeScript
+  lint and production build pass; full and production-only npm audits both report zero
+  vulnerabilities.
+- Exact next action: commit/push, take a verified pre-deployment backup, redeploy to
+  Unraid, then run migration, health, browser and full Playwright acceptance.