fix: fix disconnect when selecting firmware for dfu

lib/controller/bluetooth.dart

@@ -14,6 +14,13 @@ part 'bluetooth.g.dart';
 
 final log = Logger('BluetoothController');
 
+final backgroundBluetoothDisconnectSuppressionCountProvider =
+    StateProvider<int>((ref) => 0);
+
+final backgroundBluetoothDisconnectSuppressedProvider = Provider<bool>((ref) {
+  return ref.watch(backgroundBluetoothDisconnectSuppressionCountProvider) > 0;
+});
+
 @Riverpod(keepAlive: true)
 FlutterReactiveBle reactiveBle(Ref ref) {
   ref.keepAlive();

lib/main.dart

@@ -57,6 +57,9 @@ class _AbawoBtAppState extends ConsumerState<AbawoBtApp>
   void didChangeAppLifecycleState(AppLifecycleState state) {
     if (state == AppLifecycleState.hidden ||
         state == AppLifecycleState.paused) {
+      if (ref.read(backgroundBluetoothDisconnectSuppressedProvider)) {
+        return;
+      }
       unawaited(_disconnectBluetoothForBackground());
     }
   }

lib/pages/device_details_page.dart

@@ -549,8 +549,19 @@ class _DeviceDetailsPageState extends ConsumerState<DeviceDetailsPage> {
       _firmwareUserMessage = null;
     });
 
-    final result =
+    final suppressionCount = ref.read(
+      backgroundBluetoothDisconnectSuppressionCountProvider.notifier,
+    );
+    suppressionCount.state += 1;
+
+    final FirmwareFileSelectionResult result;
+    try {
+      result =
           await _firmwareFileSelectionService.selectAndPrepareBootloaderDfu();
+    } finally {
+      suppressionCount.state =
+          suppressionCount.state <= 0 ? 0 : suppressionCount.state - 1;
+    }
     if (!mounted) {
       return;
     }