App 2.6.0: floating button to open the app

The MG4's launcher does not list third-party apps, so the app could
only be opened by reinstalling it. Now a small round MG-red button
floats over the car's screens: tap opens the app, drag moves it (the
position is kept and clamped to the screen), and it hides while the
app itself is open. A switch in the Upload tab turns it off.

The always-on service owns the overlay, so the button is there from
boot. It needs the overlay permission (SYSTEM_ALERT_WINDOW), which the
car build has through the system UID; without it, or if the window
manager refuses, the button stays away and nothing crashes, and the
Upload tab offers the system permission screen.

Tested on an Android 9 AOSP emulator at the head unit's 1920x1080 /
160 dpi with the car APK (installs as UID 1000): button appears over
the home screen, tap opens the app, hidden while open, drag moves it
without opening the app, position survives a force-stop, the switch
works through the UI. FloatingButtonGeometry has 3 unit tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QLJfZQZeAKAwSqViTmLzki

app/src/main/java/com/evsuite/abrp/AbrpUploadService.java

@@ -67,6 +67,7 @@ public class AbrpUploadService extends Service {
     private ConsumptionCloudClient consumptionCloudClient;
     private ChargeSessionTracker chargeSessionTracker;
     private TelemetryUploader telemetryUploader;
+    private FloatingButton floatingButton;
     private WifiAutoConnect wifi;
     private ScheduledExecutorService scheduler;
     private SharedPreferences prefs;
@@ -98,6 +99,9 @@ public class AbrpUploadService extends Service {
         chargeSessionTracker = ChargeSessionTracker.get(getApplicationContext());
         wifi = new WifiAutoConnect(getApplicationContext());
         telemetryUploader = new TelemetryUploader(getApplicationContext());
+        // onCreate runs on the main thread, where the overlay window must be added.
+        floatingButton = new FloatingButton(this, prefs);
+        FloatingButton.attach(floatingButton);
 
         scheduler.scheduleWithFixedDelay(
                 this::safeUploadCycle,
@@ -139,6 +143,7 @@ public class AbrpUploadService extends Service {
         prefs.edit().putBoolean("service_running", false).apply();
         if (scheduler != null) scheduler.shutdownNow();
         if (telemetryUploader != null) telemetryUploader.stop();
+        if (floatingButton != null) FloatingButton.detach(floatingButton);
         Log.i(TAG, "Service stopped");
     }