review(mailu): M2 PASS @2026-06-11T21:15Z — build #483 LEVEL 5, fresh independent re-trigger; all phase DoD satisfied

Independent cold pass: Adversary posted !testme on PR#3 (comment #14363); build #483 reached
LEVEL 5 (install/upgrade/backup_restore/functional/lint all pass); both Maildir tests pass again
(test_backup_captures_mail_message + test_restore_returns_mail_message); clean_teardown+no_secret_leak
true; DEFERRED closed; levels reconciled; PARITY.md dual-volume; operator summary complete.
Phase mailu DONE. Builder cleared for ## DONE in STATUS-mailu.md.

machine-docs/REVIEW-mailu.md

@@ -135,3 +135,56 @@ ADV-mailu-01 is closed.
 **ADV-mailu-01 closed** — fix is real, CI proves it, no weakening of any assertion.
 
 Builder is cleared to proceed to M2.
+
+---
+
+## M2 PASS @2026-06-11T21:15Z
+
+**Claim**: DEFERRED closed; levels reconciled; PARITY.md updated; operator summary written; fresh Adversary re-trigger via independent `!testme` on PR#3.
+
+**Verdict: PASS** — all M2 DoD items verified independently. Phase `mailu` is DONE.
+
+### What I verified (cold)
+
+1. **PR#3 still open, unmerged** (Gitea API cold check):
+   - state: open, head sha: `edc0201a79d36bc87696b0f93f1ee88ad7bd10ed`, merged: False ✓
+
+2. **DEFERRED.md mailu entry closed**:
+   - Entry `2026-05-29 — mailu: no backup config` marked `[x] CLOSED @2026-06-11` with PR#3 +
+     build #477 pointers; re-entry checkbox also ticked ✓
+
+3. **PARITY.md updated with dual-volume evidence** (`tests/mailu/PARITY.md`):
+   - P4 section now states "earned via recipe-mirror PR#3" ✓
+   - Documents both `/data` (SQLite) and `/mail` (Maildir) seeded + wiped + verified restored ✓
+   - `ops.py`, `test_backup.py`, `test_restore.py` each described correctly ✓
+   - Before/after level: `backup_capable=False → L4-skip` → `backup_capable=True → L5-earned` ✓
+
+4. **Levels reconciliation independently verified**:
+   - `runner/harness/generic.py::backup_capable()` scans `compose*.yml` for `backupbot.backup.*true` ✓
+   - Main branch: no backupbot labels → `backup_capable=False` → backup rung = intentional skip → **L4** ✓
+   - PR#3 head: admin+imap labels present → `backup_capable=True` → backup rung earned → **L5** ✓
+
+5. **Operator summary in STATUS-mailu.md**: complete, accurate, actionable — specifies PR#3 URL,
+   head SHA, what the PR adds, what CI proved, what operator must do (merge PR#3) ✓
+
+6. **Fresh independent re-trigger** (Adversary posted `!testme` on PR#3 at 2026-06-11T21:04:39Z,
+   comment #14363):
+   - **Drone build #483**: LEVEL 5 SUCCESS, recipe=mailu, PR=3, ref=`edc0201a79d3`
+   - All 5 rungs PASS: install / upgrade / backup+restore / functional / lint ✓
+   - Backup stage: `test_backup_captures_mailbox` PASS (1377ms) + `test_backup_captures_mail_message` PASS (149ms) ✓
+   - Restore stage: `test_restore_returns_mailbox` PASS (1402ms) + `test_restore_returns_mail_message` PASS (168ms) ✓
+   - `clean_teardown: true`, `no_secret_leak: true` ✓
+   - No mailu stacks or volumes on host post-run (`docker stack ls` + `docker volume ls` confirm) ✓
+   - Result is reproducible: two independent builds (#477, #483) both LEVEL 5 at the same PR head ✓
+
+### Phase DoD satisfied
+
+All items from `plan-phase-mailu-backup.md` §5:
+- Mirror PR open with evidence-justified backupbot v2 labels ✓ (PR#3)
+- backup→wipe→restore proven on real seeded mail data at PR head incl. drone path ✓ (builds #477 + #483)
+- mailu's backup rung earned (not skipped) with levels reconciled ✓
+- DEFERRED closed ✓
+- M1 + M2 fresh Adversary PASSes ✓ (this entry + M1 PASS above)
+- PR unmerged for the operator ✓
+
+**Phase `mailu` is complete. Builder is cleared to write `## DONE` to STATUS-mailu.md.**