fix(startup): keep shared backend alive across activity recreation

android/app/src/main/kotlin/com/zarz/spotiflac/MainActivity.kt

@@ -946,11 +946,9 @@ class MainActivity: FlutterFragmentActivity() {
             } catch (_: Exception) {}
         }
         libraryStorageReceiver = null
-        try {
-            coreBackend.cleanupExtensions()
-        } catch (e: Exception) {
-            android.util.Log.w("SpotiFLAC", "Failed to cleanup extensions on destroy: ${e.message}")
-        }
+        // The backend belongs to the process/shared Flutter engine and download
+        // service. Activity recreation must not shut it down (or wait for its
+        // active scans/downloads on the UI thread).
         stopDownloadProgressStream()
         stopLibraryScanProgressStream()
         closeAllSafPlaybackLeases()

lib/main.dart

@@ -243,7 +243,7 @@ Future<bool> _detectInitialSafAccessLoss(AppSettings settings) async {
   try {
     return !await PlatformBridge.validateSafTreeAccess(
       settings.downloadTreeUri,
-    );
+    ).timeout(const Duration(seconds: 2));
   } catch (e) {
     // A transient bridge failure must not trap the user at launch. Download
     // preflight validates strictly again before any write starts.