docs: project docs, scripts, deployment configs, and evidence

docs/evidence/ops/2026-03-28/quality/COVERAGE_REMEDIATION_20260328-102456.md

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+# 2026-03-28 Q-004 Coverage Remediation Pass 12
+
+## Scope
+
+- Continue strict `Q-004` closure work after Pass 11.
+- Fully close the remaining low-coverage `frontend/admin/src/lib/http/client.ts` module before moving to the next task.
+- Re-verify closure through targeted tests plus full frontend validation.
+
+## Changes
+
+### Frontend
+
+- Extended module coverage in:
+  - `frontend/admin/src/lib/http/client.test.ts`
+- Newly covered behavior includes:
+  - business-error refresh rejection and session cleanup
+  - request retry during an already in-flight refresh
+  - failed shared-refresh retry when no access token remains
+  - caller-provided `AbortSignal` propagation
+  - download retry path that still ends in `401`
+- Hardened refresh hygiene in:
+  - `frontend/admin/src/lib/http/client.ts`
+- Production code change:
+  - the cached shared refresh promise is now stored as a non-rejecting waiter promise
+  - this keeps concurrent waiters working while avoiding an unhandled rejected promise when refresh fails
+
+### Backend
+
+- No backend code changes were required in this pass.
+
+## Verified Commands
+
+```powershell
+cd D:\project\frontend\admin
+npm.cmd run test:run -- src/lib/http/client.test.ts
+npm.cmd run lint
+npm.cmd run build
+npm.cmd run test:coverage
+```
+
+## Results
+
+### Frontend coverage
+
+- Overall:
+  - statements `83.86%`
+  - branches `72.68%`
+  - functions `79.87%`
+  - lines `84.72%`
+- Target areas:
+  - `src/lib/http/client.ts`: statements `100%`, branches `92.30%`, functions `100%`, lines `100%`
+  - `src/lib/http/csrf.ts`: statements `100%`, branches `88.46%`, functions `100%`, lines `100%`
+  - `src/pages/admin/ProfileSecurityPage/ProfileSecurityPage.tsx`: statements `70.17%`, branches `48.97%`, functions `67.92%`, lines `70.40%`
+
+## Validation Notes
+
+- Frontend full coverage now completes with `42` passing test files and `193` passing tests.
+- The required sequential frontend validation path passed:
+  - `test:run -- src/lib/http/client.test.ts`
+  - `lint`
+  - `build`
+  - `test:coverage`
+- The successful frontend coverage run still emits one post-summary jsdom `AggregateError` network-noise line.
+  - It does not fail the command.
+  - It remains a real validation-hygiene issue and should continue to be tracked honestly.
+
+## Real Conclusion
+
+- `src/lib/http/client.ts` is no longer an open `Q-004` gap.
+- The `lib/http` hotspot is now closure-grade for the targeted modules covered in this pass.
+- `Q-004` still cannot be honestly declared closed.
+- The remaining highest-value frontend gap is now more concentrated in:
+  - deeper remaining `ProfileSecurityPage` branches
+  - the post-summary jsdom `AggregateError` coverage-noise hygiene issue