docs: update for v1.5.0 features

- Add PKI audit logging, request duration metrics to features list
- Update test count from 216 to 283
- Add audit.py and metrics.py to project structure
- Document audit logging in api.md
- Update TASKLIST.md with completed tasks
- Update TODO.md (remove resolved debt items)
- Update ROADMAP.md decision log

TASKLIST.md

@@ -23,8 +23,6 @@ Prioritized, actionable tasks. Each task is small and completable in one session
 | Status | Task
 |--------|--------------------------------------------------------------
 | ☐      | Fix mypy type errors (currently ignored)
-| ☐      | Add test for concurrent identical submissions
-| ☐      | Add integration tests for container deployment
 
 ## Priority 4: Documentation
 
@@ -37,6 +35,11 @@ Prioritized, actionable tasks. Each task is small and completable in one session
 
 | Date       | Task
 |------------|--------------------------------------------------------------
+| 2024-12    | Integrate PKI audit logging (CERT_ISSUED, CERT_REVOKED, AUTH_FAILURE)
+| 2024-12    | Integrate request duration metrics (Prometheus histogram)
+| 2024-12    | Add memory leak detection tests (tracemalloc)
+| 2024-12    | Add concurrent paste creation tests
+| 2024-12    | Add container deployment integration tests
 | 2024-12    | Add tiered auto-expiry (anon/untrusted/trusted)
 | 2024-12    | Add admin list all pastes (`--all` flag)
 | 2024-12    | Add batch delete with confirmation (`--confirm N`)