feat: better pairing broken notification

test/util/bluetooth_settings_test.dart

@@ -0,0 +1,23 @@
+import 'package:abawo_bt_app/util/bluetooth_settings.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('isBluetoothPairingRecoveryError', () {
+    test('detects immediate disconnect connection failures', () {
+      expect(
+        isBluetoothPairingRecoveryError(
+          'Failed to connect to device-id: disconnected',
+        ),
+        isTrue,
+      );
+    });
+
+    test('does not classify generic connection failures as pairing recovery',
+        () {
+      expect(
+        isBluetoothPairingRecoveryError('Timed out connecting to device-id'),
+        isFalse,
+      );
+    });
+  });
+}