feat: Add repeater discovery onboarding flow

test/widgets/connection_dialog_test.dart

@@ -0,0 +1,67 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:meshcore_sar_app/l10n/app_localizations.dart';
+import 'package:meshcore_sar_app/providers/connection_provider.dart';
+import 'package:meshcore_sar_app/widgets/connection_dialog.dart';
+import 'package:provider/provider.dart';
+
+class _FakeConnectionProvider extends ConnectionProvider {
+  int startScanCalls = 0;
+  int stopScanCalls = 0;
+  bool _isScanning = false;
+
+  @override
+  bool get isScanning => _isScanning;
+
+  @override
+  List<ScannedDevice> get scannedDevices => const [];
+
+  @override
+  String? get error => null;
+
+  @override
+  Future<void> startScan() async {
+    startScanCalls += 1;
+    _isScanning = true;
+    notifyListeners();
+  }
+
+  @override
+  Future<void> stopScan() async {
+    stopScanCalls += 1;
+    _isScanning = false;
+    notifyListeners();
+  }
+}
+
+void main() {
+  testWidgets('BLE scan waits for explicit user action', (tester) async {
+    final connectionProvider = _FakeConnectionProvider();
+
+    await tester.pumpWidget(
+      ChangeNotifierProvider<ConnectionProvider>.value(
+        value: connectionProvider,
+        child: MaterialApp(
+          localizationsDelegates: AppLocalizations.localizationsDelegates,
+          supportedLocales: AppLocalizations.supportedLocales,
+          home: const Scaffold(body: ConnectionDialog()),
+        ),
+      ),
+    );
+
+    await tester.pump();
+
+    expect(connectionProvider.startScanCalls, 0);
+    expect(
+      find.text('Press scan to search for nearby devices'),
+      findsOneWidget,
+    );
+    expect(find.text('Scan'), findsOneWidget);
+
+    await tester.tap(find.widgetWithText(FilledButton, 'Scan'));
+    await tester.pump();
+
+    expect(connectionProvider.stopScanCalls, 1);
+    expect(connectionProvider.startScanCalls, 1);
+  });
+}