docs(06-02): complete template workflow replacement plan

- Create 06-02-SUMMARY.md documenting month-picker generation workflow
- Update STATE.md: progress 100%, decisions, session info
- Update ROADMAP.md: Phase 06 marked Complete (2/2 summaries)
- Mark TMPL-03 and TMPL-06 complete in REQUIREMENTS.md

.planning/ROADMAP.md

@@ -106,7 +106,7 @@ Plans:
   2. The template management page lets the user add, remove, and reorder fixed and variable items without leaving the page
   3. When adding a budget item (fixed or variable), the user can tag it inline as fixed, variable, or one-off
   4. The "copy from previous month" button is no longer visible anywhere in the app
-**Plans:** 1/2 plans executed
+**Plans:** 2/2 plans complete
 
 Plans:
 - [ ] 06-01-PLAN.md — Template API client, useTemplate hook, TemplatePage with add/remove/reorder, routing and i18n
@@ -153,6 +153,6 @@ Phases execute in numeric order: 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7 -> 8
 | 3. Interaction Quality and Completeness | v1.0 | 4/4 | Complete | 2026-03-12 |
 | 4. Chart Polish and Bug Fixes | v1.0 | 2/2 | Complete | 2026-03-12 |
 | 5. Template Data Model and API | v1.1 | 2/2 | Complete | 2026-03-12 |
-| 6. Template Frontend and Workflow Replacement | 1/2 | In Progress|  | - |
+| 6. Template Frontend and Workflow Replacement | 2/2 | Complete   | 2026-03-12 | - |
 | 7. Quick-Add Library | v1.1 | 0/2 | Not started | - |
 | 8. Layout and Density Rethink | v1.1 | 0/2 | Not started | - |