feat: support custom tracker url (#59)

ui/flutter/lib/pages/root/root_controller.dart

@@ -1,20 +1,4 @@
 import 'package:get/get.dart';
+import '../../api/api.dart';
 
-class RootController extends GetxController {
-  //TODO: Implement RootController
-
-  final count = 0.obs;
-  @override
-  void onInit() {
-    super.onInit();
-  }
-
-  @override
-  void onReady() {
-    super.onReady();
-  }
-
-  @override
-  void onClose() {}
-  void increment() => count.value++;
-}
+class RootController extends GetxController {}