feat: task detail view (#633)

ui/flutter/lib/app/modules/task/controllers/task_controller.dart

@@ -1,5 +1,10 @@
+import 'package:flutter/material.dart';
 import 'package:get/get.dart';
+import 'package:gopeed/api/model/task.dart';
 
 class TaskController extends GetxController {
   final tabIndex = 0.obs;
+  final scaffoldKey = GlobalKey<ScaffoldState>();
+  final selectTask = Rx<Task?>(null);
+  final copyUrlDone = false.obs;
 }