docs: consolidate restore documentation into ops/restore-tests

- merge RESTORE_HANDBOOK.md into ops/restore-tests/README.md (single
  operations doc; restore status lives only in RESTORE_MATRIX maturity
  table)
- RESTORE_MATRIX.md: extract embedded runbook drafts (261 -> 141 lines);
  unraid-flash and tailscale stubs become ops/restore-tests runbooks,
  adguard/redis checklists superseded by validated scripts
- delete six historical pre-first-run *-plan.md files (runbook + script
  are the source of truth since the validated first runs)
- SERVICES_RECOVERY: drop completed task table; DISASTER_RECOVERY:
  point related docs and section 11 to MASTER_TODO/schedule

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/README.md

@@ -20,7 +20,6 @@ Diese Datei trennt aktive Betriebsdokumentation von historischer Arbeitsdoku. Ne
 |---|---|
 | `DISASTER_RECOVERY.md` | Wiederanlauf nach Host-/Systemausfall |
 | `RESTORE_MATRIX.md` | Restore-Quellen, Dumps, Secrets und Smoke-Tests je Dienst |
-| `RESTORE_HANDBOOK.md` | praktische Restore-Anleitung |
 | `SERVICES_RECOVERY.md` | Gitea-/Komodo-/Services-Bootstrap |
 | `ROLLBACK.md` | Rueckweg bei GitOps-/Deploy-Fehlern |
 | `GITOPS_DRIFT_RUNBOOK.md` | Pflichtmatrix bei Drift zwischen Git, Komodo, Docker und Host |