chore(conc): M2 merge-integrity pre-check — merged main == M1-verified tree (not a verdict)

REVIEW-conc.md

@@ -194,3 +194,20 @@ NON-BLOCKING NOTES (carry to M2 live-verify; none gate M1):
 CONCLUSION: M1 — implementation verified — PASS. M2 (merge to main + live verification a–d) is
 unblocked. Reminder for both loops: recipe-mirror PRs are !testme targets only — never merge/push
 them. (After this verdict I may consult JOURNAL-conc to contextualize, per §6.1.)
+
+## 2026-06-10T04:49Z — M2 merge integrity pre-check (M2 NOT yet claimed — not a verdict)
+
+Builder merged the branch to main (merge commit `bb5eb3d`, 2 parents 83a6c6e∘d3fe9e2, no force)
+after my M1 PASS, and is mid-M2 live verification (journal: M2(a) cancel-mid-run evidence, (b)
+parallel runs triggered). No `claim(conc): M2` commit yet; STATUS-conc still shows the stale M1
+line (Builder's file — will update at the M2 claim). Independent merge check:
+- `git diff bb5eb3d d3fe9e2 -- runner/ .drone.yml docs/concurrency.md tests/ nix/` = EMPTY → the
+  merge preserved EXACTLY the code I cold-verified at M1. No conflict-resolution drift introduced.
+- `git merge-base --is-ancestor d3fe9e2 bb5eb3d` = true.
+So deployed main == M1-verified tree. At the M2 claim I therefore re-verify only LIVE behavior +
+the push build, not the code again:
+  push build green; (a) cancel mid-run → no leaked python/lock, next janitor reaps the app, zero
+  leakage; (b) two parallel !testme (immich#2 + plausible#3) → both green, zero leakage; (c)
+  double-!testme same PR → 2nd blocks on the app lock (visible in its drone log) then runs; (d) one
+  full green end-to-end run. Evidence to come from Drone build logs + cc-ci state (abra app ls /
+  lslocks / docker), cold from my own access path.