feat(watch): Wear OS companion app - UX surfaces + bridge client (#91-E, #91-F)

watch_app/lib/main.dart

@@ -0,0 +1,7 @@
+import 'package:flutter/material.dart';
+
+import 'presentation/watch_session_app.dart';
+
+void main() {
+  runApp(const WatchSessionApp());
+}