Add the Fly Agent App, a Remote ID companion to DJI Fly

A Flutter app that runs next to DJI Fly without the DJI SDK. It receives the
aircraft's Remote ID (Bluetooth, BT5, Wi-Fi NaN and Beacon) in a foreground
service, streams the paired aircraft to the hub over /ws/device, and turns
take-off to landing into a logbook entry filed through /api/flights, queued
when offline. Covers phases A0-A3 of the Fly Agent plan; needs no server change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Fly Agent App/android/app/src/debug/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+    <!-- The INTERNET permission is required for development. Specifically,
+         the Flutter tool needs it to communicate with the running application
+         to allow setting breakpoints, to provide hot reload, etc.
+    -->
+    <uses-permission android:name="android.permission.INTERNET"/>
+</manifest>