docs(14-05): complete SQLite-to-Postgres migration script plan

- SUMMARY.md with execution results
- STATE.md updated with plan 05 completion
- ROADMAP.md updated with phase 14 progress
- DB-04 requirement marked complete

.planning/ROADMAP.md

@@ -188,7 +188,7 @@ Plans:
 | 11. Candidate Ranking | v1.3 | 2/2 | Complete | 2026-03-16 |
 | 12. Comparison View | v1.3 | 1/1 | Complete | 2026-03-17 |
 | 13. Setup Impact Preview | v1.3 | 0/2 | Not started | - |
-| 14. PostgreSQL Migration | v2.0 | 0/? | Not started | - |
+| 14. PostgreSQL Migration | v2.0 | 5/6 | In Progress | — |
 | 15. External Authentication | v2.0 | 0/? | Not started | - |
 | 16. Multi-User Data Model | v2.0 | 0/? | Not started | - |
 | 17. Object Storage | v2.0 | 0/? | Not started | - |