fix(lints): await asynchronous work in guarded blocks

lib/services/platform_bridge.dart

@@ -2128,7 +2128,7 @@ class PlatformBridge {
       try {
         final contents = await file.readAsString();
         if (contents.isEmpty) return null;
-        return _decodeJsonStringAsync(contents);
+        return await _decodeJsonStringAsync(contents);
       } finally {
         try {
           await file.delete();

lib/utils/extension_auth_launcher.dart

@@ -100,7 +100,7 @@ Future<bool> openPendingExtensionVerification(
       _log.w(
         'Could not open verification challenge for $normalizedExtensionId',
       );
-      return showExtensionVerificationHelpDialog(
+      return await showExtensionVerificationHelpDialog(
         normalizedExtensionId,
         uri,
         browserMode: browserMode,

lib/utils/saf_display_path.dart

@@ -49,8 +49,8 @@ String buildSafFileDisplayPath({
   if (displayRoot != null) {
     return [
       displayRoot.replaceAll(RegExp(r'/+$'), ''),
-      if (cleanRelativeDir != null) cleanRelativeDir,
-      if (cleanFileName != null) cleanFileName,
+      ?cleanRelativeDir,
+      ?cleanFileName,
     ].join('/');
   }
 

lib/widgets/audio_analysis_widget.dart

@@ -905,7 +905,7 @@ class _AudioAnalysisCardState extends State<AudioAnalysisCard> {
       final bytes = await file.readAsBytes();
       final completer = Completer<ui.Image>();
       ui.decodeImageFromList(bytes, completer.complete);
-      return completer.future;
+      return await completer.future;
     } catch (_) {
       return null;
     }