docs(03-01): complete link record extraction and wiki-link resolution plan

- 03-01-SUMMARY.md: documents LinkRecord struct, render_markdown signature change,
  resolve_wiki_link algorithm, is_within_vault guard, and all decisions
- STATE.md: advance to Phase 3 Plan 2, update progress to 75%, add 3 decisions,
  mark NAV path traversal blocker resolved
- ROADMAP.md: update phase 3 plan progress (1 of 2 summaries)
- REQUIREMENTS.md: mark NAV-01, NAV-02, NAV-10 complete

.planning/ROADMAP.md

@@ -61,7 +61,7 @@ Plans:
   3. User can press Backspace or a back key to return to the previous document, and then press a forward key to return to where they were
   4. User can Tab-cycle between links on a page to select and follow them without using a mouse
   5. User sees their current location (breadcrumb) in the status bar
-**Plans:** 2 plans
+**Plans:** 1/2 plans executed
 Plans:
 - [ ] 03-01-PLAN.md — Renderer link extraction, wiki-link styling, and vault link resolution
 - [ ] 03-02-PLAN.md — App navigation: history, link cycling, draw-time selection, breadcrumb status bar
@@ -86,5 +86,5 @@ Phases execute in numeric order: 1 → 2 → 3 → 4
 |-------|----------------|--------|-----------|
 | 1. Safety Foundation | 3/3 | Complete    | 2026-02-28 |
 | 2. Vault Core and Rendering | 3/3 | Complete    | 2026-02-28 |
-| 3. Navigation and Links | 0/2 | Not started | - |
+| 3. Navigation and Links | 1/2 | In Progress|  |
 | 4. BBS Polish and Live Content | 0/TBD | Not started | - |