docs(02-03): complete visual verification plan for planning threads

- All four THRD requirements verified working end-to-end in browser
- Phase 2 complete, STATE.md and ROADMAP.md updated

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.planning/ROADMAP.md

@@ -13,7 +13,7 @@ GearBox delivers a gear management and purchase planning web app in three phases
 Decimal phases appear between their surrounding integers in numeric order.
 
 - [x] **Phase 1: Foundation and Collection** - Project scaffolding, data model, and complete gear item CRUD with categories and totals (completed 2026-03-14)
-- [ ] **Phase 2: Planning Threads** - Purchase research workflow with candidates, comparison, and thread resolution
+- [x] **Phase 2: Planning Threads** - Purchase research workflow with candidates, comparison, and thread resolution (completed 2026-03-15)
 - [ ] **Phase 3: Setups and Dashboard** - Named loadouts from collection items and dashboard home page
 
 ## Phase Details
@@ -45,7 +45,7 @@ Plans:
   2. User can add candidate products to a thread with weight, price, notes, and product link
   3. User can edit and remove candidates from an active thread
   4. User can resolve a thread by selecting a winning candidate, which automatically creates a new item in their collection and archives the thread
-**Plans:** 2/3 plans executed
+**Plans:** 3/3 plans complete
 
 Plans:
 - [ ] 02-01-PLAN.md — Backend API: thread/candidate CRUD, resolution transaction, with TDD
@@ -75,5 +75,5 @@ Phases execute in numeric order: 1 -> 2 -> 3
 | Phase | Plans Complete | Status | Completed |
 |-------|----------------|--------|-----------|
 | 1. Foundation and Collection | 4/4 | Complete    | 2026-03-14 |
-| 2. Planning Threads | 2/3 | In Progress|  |
+| 2. Planning Threads | 3/3 | Complete   | 2026-03-15 |
 | 3. Setups and Dashboard | 0/0 | Not started | - |