fix(download): preserve SAF and defer background starts

test/download_start_policy_test.dart

@@ -0,0 +1,54 @@
+import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:spotiflac_android/providers/download_queue_provider.dart';
+import 'package:spotiflac_android/services/platform_bridge.dart';
+
+void main() {
+  group('download storage recovery', () {
+    test('requires reauthorization instead of redirecting SAF downloads', () {
+      expect(
+        storageWriteRecoveryFor(useSaf: true),
+        StorageWriteRecovery.requestSafAccess,
+      );
+    });
+
+    test('keeps automatic fallback for app-managed folders', () {
+      expect(
+        storageWriteRecoveryFor(useSaf: false),
+        StorageWriteRecovery.useAppFolderFallback,
+      );
+    });
+  });
+
+  group('foreground download start policy', () {
+    test('allows service launch only while the app is resumed', () {
+      expect(
+        canStartForegroundDownloadForLifecycle(AppLifecycleState.resumed),
+        isTrue,
+      );
+      expect(
+        canStartForegroundDownloadForLifecycle(AppLifecycleState.inactive),
+        isFalse,
+      );
+      expect(
+        canStartForegroundDownloadForLifecycle(AppLifecycleState.paused),
+        isFalse,
+      );
+      expect(canStartForegroundDownloadForLifecycle(null), isFalse);
+    });
+
+    test('recognizes the typed platform denial', () {
+      expect(
+        isForegroundServiceStartNotAllowed(
+          PlatformException(code: foregroundServiceStartNotAllowedCode),
+        ),
+        isTrue,
+      );
+      expect(
+        isForegroundServiceStartNotAllowed(PlatformException(code: 'ERROR')),
+        isFalse,
+      );
+    });
+  });
+}