docs(08-02): complete task delete UI plan

- Add 08-02-SUMMARY.md with delete button and smartDeleteTask outcomes
- Update STATE.md with progress, decisions, and session continuity
- Update ROADMAP.md: phase 08-task-delete 2/2 plans complete
- Mark DEL-01 and DEL-04 requirements complete

.planning/REQUIREMENTS.md

@@ -9,10 +9,10 @@ Requirements for milestone v1.2 Polish & Task Management. Each maps to roadmap p
 
 ### Task Delete
 
-- [ ] **DEL-01**: User can delete a task from the task edit form via a clearly visible delete action
+- [x] **DEL-01**: User can delete a task from the task edit form via a clearly visible delete action
 - [x] **DEL-02**: Deleting a task that has never been completed removes it from the database entirely (hard delete)
 - [x] **DEL-03**: Deleting a task that has been completed at least once deactivates it instead (soft delete) — task is hidden from all active views but preserved in the database for future statistics
-- [ ] **DEL-04**: User sees a confirmation before deleting/deactivating a task
+- [x] **DEL-04**: User sees a confirmation before deleting/deactivating a task
 
 ### Task Creation UX