diff --git a/docs/BACKLOG.md b/docs/BACKLOG.md
index 4c2c49cc5..1ee914dca 100644
--- a/docs/BACKLOG.md
+++ b/docs/BACKLOG.md
@@ -679,6 +679,6 @@ are closed (status: closed in frontmatter)._
 - [ ] **[B-0536](backlog/P3/B-0536-orphan-ferry-ref-cleanup-and-audit-false-positives-2026-05-15.md)** Orphan-ferry-ref cleanup + audit false-positive on filename paths
 - [ ] **[B-0537](backlog/P3/B-0537-memory-md-index-entry-lengths-cleanup-and-gate-2026-05-15.md)** memory/MEMORY.md index-entry length cleanup (100 long entries) + CI gate
 - [ ] **[B-0553](backlog/P3/B-0553-audit-backlog-status-drift-detection-2026-05-16.md)** Backlog status-drift auditor — detect `status: open` rows whose primary artifact has already shipped
-- [ ] **[B-0557](backlog/P3/B-0557-audit-backlog-status-drift-quality-improvements-2026-05-16.md)** Audit-backlog-status-drift — quality improvements per PR #3758 reviewer findings
+- [x] **[B-0557](backlog/P3/B-0557-audit-backlog-status-drift-quality-improvements-2026-05-16.md)** Audit-backlog-status-drift — quality improvements per PR #3758 reviewer findings
 
 <!-- END AUTO-GENERATED -->
diff --git a/docs/backlog/P3/B-0557-audit-backlog-status-drift-quality-improvements-2026-05-16.md b/docs/backlog/P3/B-0557-audit-backlog-status-drift-quality-improvements-2026-05-16.md
index 32f464f74..fb43f4bab 100644
--- a/docs/backlog/P3/B-0557-audit-backlog-status-drift-quality-improvements-2026-05-16.md
+++ b/docs/backlog/P3/B-0557-audit-backlog-status-drift-quality-improvements-2026-05-16.md
@@ -1,12 +1,13 @@
 ---
 id: B-0557
 priority: P3
-status: open
+status: closed
 title: "Audit-backlog-status-drift — quality improvements per PR #3758 reviewer findings"
 tier: factory-hygiene
 effort: S
 created: 2026-05-16
 last_updated: 2026-05-16
+closed: 2026-05-16
 depends_on: [B-0553]
 composes_with: [B-0553]
 tags: [audit, hygiene, follow-up, reviewer-findings, mechanization]
@@ -76,3 +77,20 @@ Same as B-0553 — friction-reducer. Each improvement is small and additive; tog
 ## Origin tick
 
 Tick 15 of the 2026-05-16 session. PR #3758 review-cycle 2 produced these 4 findings on commit `e5e7143`; this row captures them as follow-up substrate so PR #3758 can ship cleanly.
+
+## Resolution (2026-05-16)
+
+All four slices shipped within the same 2026-05-16 session that filed this row:
+
+| Slice | Finding | PR | Merge commit |
+|---|---|---|---|
+| 1 | `--check` flag for CI integration | [#3783](https://github.com/Lucent-Financial-Group/Zeta/pull/3783) | `0a57a814` |
+| 2 | try/catch on FS reads (don't abort on bad file) | [#3788](https://github.com/Lucent-Financial-Group/Zeta/pull/3788) | `6809f6e3` |
+| 3 | chdir to repo root via `git rev-parse` (cwd-independent) + 2 regression tests | [#3790](https://github.com/Lucent-Financial-Group/Zeta/pull/3790) | `472024dc` |
+| 4 | Mixed-bullet extraction (paths before cross-ref tokens are deliverables) + tsc-strict guard | [#3809](https://github.com/Lucent-Financial-Group/Zeta/pull/3809) | `eb04e3d` |
+
+**Acceptance bullets**: every bullet in the Acceptance section has a corresponding merged PR. Verified per `.claude/rules/backlog-item-start-gate.md` step 0 partial-vs-drift discriminator.
+
+**Test count**: 16 (B-0553 first slice) → 20 (after slices 3 + 4 added 2 + 2 regression tests). All passing on main.
+
+**Infrastructure-eats-itself**: this row was caught as a genuine drift candidate by the audit tool it specified. The 6-layer substrate-drift-catch infrastructure has now reached full operational closure on main.