docs(05): create phase plan

Phase 05: Search
- 3 plans in 2 waves
- Wave 1: 05-01 (UI components), 05-02 (filtering logic) — parallel
- Wave 2: 05-03 (integration + recent searches + "/" shortcut)
- Ready for execution

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -105,12 +105,12 @@ Plans:
   3. User can filter entries by date range
   4. User can filter to show only tasks or only thoughts
   5. Search results show relevant matches with highlighting
-**Plans**: TBD
+**Plans**: 3 plans
 
 Plans:
-- [ ] 05-01: TBD
-- [ ] 05-02: TBD
-- [ ] 05-03: TBD
+- [ ] 05-01-PLAN.md — SearchBar and FilterBar components with type definitions
+- [ ] 05-02-PLAN.md — Filtering logic and text highlighting utilities
+- [ ] 05-03-PLAN.md — Integration with recent searches and "/" keyboard shortcut
 
 ### Phase 6: Deployment
 **Goal**: Application runs in Docker with persistent data and easy configuration