docs(dn): record task 5 fix evidence

.superpowers/sdd/2026-09-18-hybrid-delivery-note-ingestion/task-5-report.md

@@ -20,3 +20,17 @@ Tests:
 - `git diff --check` — passed.
 
 Concerns: no production schema was applied. The route defensively sorts notes by `note_index`; posted detection covers legacy status, staged `stage=posted`, and non-empty `posted_at`.
+
+## Fix round 2 evidence
+
+Task 5 implementation/fix commit: `dd0560c2d66f013e173e432d27bfffd34a6146f3`.
+
+This round removes surplus unposted candidates during merges, captures the full before-state for the audit event, and serializes revisions through the existing unique `dn_pipeline_locks` batch lease. Live leases return 409; expired leases are reclaimed; leases release in `finally` on success, stale revision, and failure. Added coverage for merge deletion, live/reclaimed leases, release behavior, malformed payloads, staged posted candidates, and pagination conflicts. No production schema was applied.
+
+Commands and results:
+
+- `npx vitest run 'src/app/api/dn-batches/[id]/assembly/route.test.ts'` — 11 passed after test-first failures.
+- `npm run typecheck` — passed.
+- `npx vitest run src/lib/dn-pipeline src/app/api/dn-batches` — 263 passed.
+- `python3 scripts/pb-add-dn-staged-ingestion.py --dry-run` — completed; no schema changes written.
+- `git diff --check` — passed.