docs: close out MS16+MS17 mission

Mark acceptance criteria 14-28 as DONE, add MS16+MS17 to Completed Work
section, update resolved risks/open questions, close issue #469, finalize
manifest and scratchpad with smoke test confirmation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/scratchpads/prd-implementation-20260222.md

@@ -124,6 +124,28 @@ User instruction: start planning. Be complete and thorough.
 
 **Resolution needed**: Jason to check Traefik proxy logs on Coolify server (10.1.1.44). May need Traefik proxy restart or cert store cleanup.
 
+## Mission Close-Out — 2026-02-23
+
+**Smoke test**: CONFIRMED by Jason. All pages accessible, auth working, no console errors.
+
+**Deployment blocker resolution**: Traefik HTTPS routing issue resolved (was intermittent proxy state issue).
+
+**Close-out actions (S3)**:
+
+- PRD updated: MS16+MS17 added to Completed Work, acceptance criteria 14-28 marked DONE, risks/open questions marked RESOLVED
+- Issue #469 closed with completion comment
+- Manifest updated with S2+S3 session entries
+- Mission status: **COMPLETE**
+
+**Final evidence**:
+
+- 15/15 tasks done
+- 15 PRs merged (#470-#484)
+- 4 issues closed (#466-#469)
+- CI pipeline #585 green
+- All 5125 tests passing
+- Deployed and smoke-tested at mosaic.woltje.com
+
 ## Corrections
 
 (none)