docs(03): create phase 3 visual flattening plans

Phase 03: Visual Flattening
- 2 plans in 2 waves
- Plan 01: Create ItineraryFlattener utility, refactor reloadData()
- Plan 02: Add determinism tests for flattening behavior
- Ready for execution

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

.planning/ROADMAP.md

@@ -45,8 +45,8 @@ Plans:
 **Plans:** 2 plans
 
 Plans:
-- [ ] 02-01-PLAN.md - Migrate XCTest constraint tests to Swift Testing
-- [ ] 02-02-PLAN.md - Add edge case tests and document constraint API
+- [x] 02-01-PLAN.md - Migrate XCTest constraint tests to Swift Testing
+- [x] 02-02-PLAN.md - Add edge case tests and document constraint API
 
 **Requirements:**
 - CONS-01: Games cannot be moved (fixed by schedule)
@@ -68,6 +68,12 @@ Plans:
 
 **Dependencies:** Phase 2 (constraints inform what items exist per day)
 
+**Plans:** 2 plans
+
+Plans:
+- [ ] 03-01-PLAN.md - Create ItineraryFlattener utility and refactor reloadData()
+- [ ] 03-02-PLAN.md - Add determinism tests for flattening behavior
+
 **Requirements:**
 - FLAT-01: Visual flattening sorts by sortOrder within each day
 - FLAT-02: Flattening is deterministic and stateless
@@ -109,12 +115,12 @@ Plans:
 
 | Phase | Status | Requirements | Completed |
 |-------|--------|--------------|-----------|
-| 1 - Semantic Position Model | ✓ Complete | 8 | 8 |
-| 2 - Constraint Validation | Planned | 4 | 0 |
-| 3 - Visual Flattening | Not Started | 3 | 0 |
+| 1 - Semantic Position Model | Complete | 8 | 8 |
+| 2 - Constraint Validation | Complete | 4 | 4 |
+| 3 - Visual Flattening | In Progress | 3 | 0 |
 | 4 - Drag Interaction | Not Started | 8 | 0 |
 
-**Total:** 8/23 requirements completed
+**Total:** 12/23 requirements completed
 
 ---
 *Roadmap created: 2026-01-18*