refactor: enhance TimerPage layout and functionality; update theme and tokens for improved design consistency

- Refactored TimerPage component to improve layout and user experience.
- Updated theme configuration to utilize design tokens for better maintainability.
- Introduced new tokens for colors and typography to align with design principles.
- Simplified state management and improved timer functionality.
- Enhanced accessibility and responsiveness of UI elements.

desktop/kadence_desktop/api.py

@@ -100,8 +100,9 @@ class Api:
     def refresh_tasks(self) -> dict:
         return self._request("POST", "/api/tasks/refresh", {})
 
-    def task_done(self, task_id: int, done: bool = True) -> dict:
-        return self._request("POST", f"/api/tasks/{task_id}/done", {"done": done})
+    def patch_task(self, task_id: int, patch: dict) -> dict:
+        """Edit a task's local fields (pinning, estimate). Completion is not ours."""
+        return self._request("PATCH", f"/api/tasks/{task_id}", patch)
 
     def create_task(self, title: str, due_date: str | None = None) -> dict:
         return self._request("POST", "/api/tasks", {"title": title, "due_date": due_date})