M23: automate verified database backups

PROJECT_STATE.md

@@ -2537,3 +2537,20 @@ evidence yet."
   Prometheus `promtool` accepted the scrape config and all six rules; merged Compose and
   Grafana dashboard JSON validate. Exact next action: automate verified backups,
   retention and restore-readiness checks.
+
+## M23 — scheduled and retained recovery points (2026-08-10)
+
+- Added a continuously running Unraid backup service that waits for healthy PostgreSQL,
+  creates an immediate custom-format dump and repeats at a configurable interval without
+  access to the Docker socket. The existing on-demand path remains supported.
+- Every backup must pass `pg_restore --list` before publication and receives a SHA-256
+  sidecar. Retention defaults to 30 days while always preserving at least seven newest
+  restore points. An optional independently mounted secondary destination receives the
+  same verified artifacts.
+- Added a latest-success marker and container healthcheck that detects a missed 26-hour
+  recovery point, a standalone verification command, guarded destinations and bounded
+  backup/log storage.
+- Evidence: all shell scripts pass Alpine `sh -n`; merged Unraid Compose validates; a
+  disposable PostgreSQL instance produced a real dump, checksum verification passed and
+  `pg_restore --list` accepted the artifact. Exact next action: implement privacy export,
+  anonymisation safeguards, retention reporting and governance documentation.