docs(09-05): complete tooltip fix plan - hover behavior and helpTextPrefix prop

- SUMMARY.md: tooltip placement fix and hover+pin behavior documented
- STATE.md: decisions added, session updated, progress at 100%
- ROADMAP.md: Phase 9 plan 5/5 complete

.planning/ROADMAP.md

@@ -66,7 +66,7 @@ Plans:
   3. Backend selection cards and output blocks display MD3 elevation with tonal surface tint and consistent shape tokens
   4. Step indicator shows numbered circles connected by lines, with checkmarks on completed steps, highlight on current, and muted future steps
   5. FieldRenderer produces identical `aria-label` attributes for both text-branch and select-branch inputs
-**Plans:** 5 plans (4 complete + 1 gap closure)
+**Plans:** 5/5 plans complete
 Plans:
 - [x] 09-01-PLAN.md — TextFieldMD3 component, MD3 button constants, DEBT-01 aria-label fix
 - [x] 09-02-PLAN.md — StepIndicator rebuild with MD3 circles and connectors
@@ -108,6 +108,6 @@ Plans:
 | 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 | 2/2 | Complete | 2026-04-01 |
-| 9. MD3 Components | 4/4 | Complete   | 2026-04-01 | - |
+| 9. MD3 Components | 5/5 | Complete   | 2026-04-01 | - |
 | 10. Content & Clarity | v1.2 | 0/? | Not started | - |
 | 11. Polish & Responsiveness | v1.2 | 0/? | Not started | - |