docs(08-01): complete theme foundation plan 01

- SUMMARY with MD3 token system, ThemeToggle, FOUC prevention
- STATE updated: decisions, session, 97% progress
- ROADMAP phase 8 marked In Progress (1/2 plans)
- REQUIREMENTS THEME-01, THEME-02 marked complete

.planning/ROADMAP.md

@@ -51,7 +51,7 @@ Full phase details: [.planning/milestones/v1.1-ROADMAP.md](milestones/v1.1-ROADM
   2. User can toggle between System, Light, and Dark themes via a visible control, and the entire UI responds immediately
   3. Theme preference persists in localStorage and applies on reload without any flash of wrong theme
   4. Tailwind v4 `@theme` directive maps MD3 token names to utility classes (e.g., `bg-surface`, `text-on-primary`)
-**Plans:** 2 plans
+**Plans:** 1/2 plans executed
 Plans:
 - [ ] 08-01-PLAN.md — Token system, flash prevention, ThemeToggle component
 - [ ] 08-02-PLAN.md — Color class migration across all components
@@ -101,7 +101,7 @@ Plans:
 | 5. Tech Debt | v1.1 | 4/4 | Complete | 2026-03-30 |
 | 6. New Backends | v1.1 | 4/4 | Complete | 2026-03-31 |
 | 7. Validation & UX Polish | v1.1 | 3/3 | Complete | 2026-03-31 |
-| 8. Theme Foundation | v1.2 | 0/2 | Planning | - |
+| 8. Theme Foundation | 1/2 | In Progress|  | - |
 | 9. MD3 Components | v1.2 | 0/? | Not started | - |
 | 10. Content & Clarity | v1.2 | 0/? | Not started | - |
 | 11. Polish & Responsiveness | v1.2 | 0/? | Not started | - |