Replace status_id with in_progress boolean across mobile apps

- Remove TaskStatus model and status_id foreign key references
- Add in_progress boolean field to task models and forms
- Update TaskApi to use dedicated POST endpoints for task actions:
  - POST /tasks/:id/cancel/ instead of PATCH with is_cancelled
  - POST /tasks/:id/uncancel/
  - POST /tasks/:id/archive/
  - POST /tasks/:id/unarchive/
- Fix iOS TaskViewModel to use error-first pattern for Kotlin-Swift
  generic type bridging issues
- Update iOS callback signatures to pass full TaskResponse instead
  of just taskId to avoid stale closure lookups
- Add in_progress localization strings
- Update widget preview data to use inProgress boolean

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

composeApp/src/commonMain/composeResources/values/strings.xml

@@ -179,6 +179,7 @@
     <string name="tasks_unarchive">Unarchive</string>
     <string name="tasks_completed_message">Task marked as completed</string>
     <string name="tasks_in_progress_message">Task marked as in progress</string>
+    <string name="tasks_in_progress_label">In Progress</string>
     <string name="tasks_cancelled_message">Task cancelled</string>
 
     <!-- Task Completions -->