TASK22028: phase 16 memory-bank updates

memory-bank/refactor-plan-actions-index.md

@@ -505,6 +505,37 @@ Status key: `[x] done`, `[ ] pending`
     - `tests/phase15/service-behaviour.test.cjs`
 - Re-run phase6–phase15 baseline tests and lint after rollback to confirm parity.
 
+### Phase 16 completion snapshot (2026-03-13)
+
+Status key: `[x] done`, `[ ] pending`
+
+1. `[x]` Continue on current branch with separate commit for additional small slice
+    - branch: `TASK22028-phase15-hardening-slice`
+2. `[x]` Apply minimal consistency hardening in 3 file proxy handlers
+    - `pages/api/file/getbloblistproxy.js`
+    - `pages/api/file/getrepsblobproxy.js`
+    - `pages/api/file/getawaitingsubmissionfromblobproxy.js`
+3. `[x]` Standardize required-input guard pattern
+    - added local `hasValue` checks for required params
+    - removed unused/dead imports/constants in touched files
+4. `[x]` Add focused Phase 16 tests
+    - added `tests/phase16/service-behaviour.test.cjs`
+    - missing-input negative-path checks + one valid-input contract check
+5. `[x]` Execute validation bundle
+    - phase6 parity + phase6–phase16 behaviour tests pass
+    - lint warnings only (pre-existing)
+6. `[x]` Execute manual checks
+    - missing required-input proxy calls -> 400
+
+### Phase 16 rollback notes
+
+- Revert commit `c196edb` (or files):
+    - `pages/api/file/getbloblistproxy.js`
+    - `pages/api/file/getrepsblobproxy.js`
+    - `pages/api/file/getawaitingsubmissionfromblobproxy.js`
+    - `tests/phase16/service-behaviour.test.cjs`
+- Re-run phase6–phase16 baseline tests and lint.
+
 ## Safe execution mode for migration chunks (required)
 
 To reduce terminal hangs during bulk migration work, run refactor chunks in **safe stepwise mode** instead of long chained commands.