Project task view: tapping a project shows milestone-grouped task list

- ProjectLibraryCard.onTap navigates to /projects/:id/tasks
- New ProjectTasksScreen: milestone sections with coloured dot,
  done/total counter and thin progress bar; unassigned tasks at bottom
- Status cycle icon updates optimistically (pendingStatus map) so
  the list doesn't flash on every tap; syncs global tasksProvider
- New route /projects/:id/tasks registered in app.dart
- TasksApi.getByProject + TasksRepository + projectTasksProvider (family)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/data/api/tasks_api.dart

@@ -52,6 +52,24 @@ class TasksApi {
     }
   }
 
+  Future<List<Task>> getByProject(int projectId) async {
+    try {
+      final response = await _dio.get(
+        '/api/notes',
+        queryParameters: {
+          'project_id': projectId,
+          'is_task': 'true',
+          'limit': 500,
+        },
+      );
+      final data = response.data as Map<String, dynamic>;
+      final list = data['notes'] as List<dynamic>;
+      return list.map((e) => Task.fromJson(e as Map<String, dynamic>)).toList();
+    } on DioException catch (e) {
+      throw dioToApp(e);
+    }
+  }
+
   Future<List<Task>> getSubTasks(int parentId) async {
     try {
       final response = await _dio.get(