* Fix Today page task completion issues
- Fix completed task border color staying as priority color
- Add isInCompletedSection prop to TaskItem for explicit completed state
- Tasks in completed section now always show green border regardless of priority
- Fixes race condition where status wasn't updated during optimistic UI update
- Fix completed task reappearing after unmarking and page refresh
- Add defensive check in backend to force clear completed_at when status is not DONE
- Add development logging in tasksService for debugging completion toggle
- Ensures database state is consistent even if handleCompletionStatus doesn't clear it
- Update TaskList and TasksToday components to pass isInCompletedSection prop
- Explicitly marks tasks rendered in the completed section
- Prevents border color flickering during state transitions
* Add comprehensive logging to debug completion issues
* Fix duplicate API requests causing completion state issues
- Separate state update logic from API call in handleTaskUpdate
- Create new updateTaskInState function for state-only updates
- Pass onTaskCompletionToggle to completed section to avoid duplicate calls
- This fixes the persistence issue where unmarked tasks came back after refresh
- Completion toggles now only make ONE API call instead of two
* Add debug logging to updateTaskInState
