docs(11-02): complete step animation and scroll-to-error plan

- Create 11-02-SUMMARY.md documenting POLISH-03 and POLISH-04 completion
- Update STATE.md: phase 11 complete, 100% progress, new decisions added
- Update ROADMAP.md: phase 11 plan progress (2/2 complete)
- Update REQUIREMENTS.md: mark POLISH-03 and POLISH-04 complete

.planning/ROADMAP.md

@@ -38,7 +38,7 @@ Full phase details: [.planning/milestones/v1.1-ROADMAP.md](milestones/v1.1-ROADM
 - [x] **Phase 8: Theme Foundation** - MD3 color token system and dark mode infrastructure (completed 2026-04-01)
 - [x] **Phase 9: MD3 Components** - UI primitives and component migration to semantic tokens (completed 2026-04-01)
 - [x] **Phase 10: Content & Clarity** - Intro section, step descriptions, and contextual help (completed 2026-04-01)
-- [ ] **Phase 11: Polish & Responsiveness** - Mobile layout, focus states, transitions, scroll-to-error
+- [x] **Phase 11: Polish & Responsiveness** - Mobile layout, focus states, transitions, scroll-to-error (completed 2026-04-01)
 
 ## Phase Details
 
@@ -98,7 +98,7 @@ Plans:
   2. Every interactive element shows a visible 3px MD3 focus outline when navigated via keyboard (using `focus-visible`)
   3. Step transitions use a subtle fade/slide animation that is suppressed when the user has `prefers-reduced-motion` enabled
   4. When form validation fails, the view auto-scrolls to the first field with an error
-**Plans:** 1/2 plans executed
+**Plans:** 2/2 plans complete
 Plans:
 - [ ] 11-01-PLAN.md — Mobile responsive layout + MD3 focus-visible indicators
 - [ ] 11-02-PLAN.md — Step transition animation + auto-scroll to first error
@@ -117,4 +117,4 @@ Plans:
 | 8. Theme Foundation | v1.2 | 2/2 | Complete | 2026-04-01 |
 | 9. MD3 Components | v1.2 | 5/5 | Complete | 2026-04-01 |
 | 10. Content & Clarity | v1.2 | 3/3 | Complete | 2026-04-01 |
-| 11. Polish & Responsiveness | 1/2 | In Progress|  | - |
+| 11. Polish & Responsiveness | 2/2 | Complete   | 2026-04-01 | - |