perf: optimize video stream processing state management

- Move isCurrentlyProcessing to widget state for better performance
- Only call setState when processing state actually changes
- Add comprehensive processing status handling (retry, compressing, uploading)
- Remove redundant service calls from build method
- Clean up unnecessary early returns and duplicate logic

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

mobile/apps/photos/lib/services/video_preview_service.dart

@@ -157,8 +157,6 @@ class VideoPreviewService {
 
   bool isCurrentlyProcessing(int? uploadedFileID) {
     if (uploadedFileID == null) return false;
-    // Check if file is actively being processed
-    if (uploadingFileId == uploadedFileID) return true;
 
     // Also check if file is in queue or other processing states
     final item = _items[uploadedFileID];

mobile/apps/photos/lib/ui/viewer/file/video_stream_change.dart

@@ -32,27 +32,34 @@ class VideoStreamChangeWidget extends StatefulWidget {
 
 class _VideoStreamChangeWidgetState extends State<VideoStreamChangeWidget> {
   StreamSubscription<VideoPreviewStateChangedEvent>? _subscription;
+  bool isCurrentlyProcessing = false;
+
   @override
   void initState() {
     super.initState();
+    // Initialize processing state safely in initState
+    isCurrentlyProcessing = VideoPreviewService.instance
+        .isCurrentlyProcessing(widget.file.uploadedFileID);
 
     _subscription =
         Bus.instance.on<VideoPreviewStateChangedEvent>().listen((event) {
       final fileId = event.fileId;
-      if (widget.file.uploadedFileID != fileId) {
-        return; // Not for this file
-      }
-
       final status = event.status;
 
-      // Handle different states
-      switch (status) {
-        case PreviewItemStatus.inQueue:
-        case PreviewItemStatus.uploaded:
-        case PreviewItemStatus.failed:
-          setState(() {});
-          break;
-        default:
+      // Handle different states - will be false for different files or non-processing states
+      final newProcessingState = widget.file.uploadedFileID == fileId && switch (status) {
+        PreviewItemStatus.inQueue ||
+        PreviewItemStatus.retry ||
+        PreviewItemStatus.compressing ||
+        PreviewItemStatus.uploading =>
+          true,
+        _ => false,
+      };
+      
+      // Only update state if value changed
+      if (isCurrentlyProcessing != newProcessingState) {
+        isCurrentlyProcessing = newProcessingState;
+        setState(() {});
       }
     });
   }
@@ -80,13 +87,10 @@ class _VideoStreamChangeWidgetState extends State<VideoStreamChangeWidget> {
     final bool isPreviewAvailable = widget.file.uploadedFileID != null &&
         (fileDataService.previewIds.containsKey(widget.file.uploadedFileID));
 
-    // Check if this file is currently being processed for streaming
-    final bool isCurrentlyProcessing = VideoPreviewService.instance
-        .isCurrentlyProcessing(widget.file.uploadedFileID);
-    
     // Get the current processing status for more specific messaging
-    final processingStatus = widget.file.uploadedFileID != null 
-        ? VideoPreviewService.instance.getProcessingStatus(widget.file.uploadedFileID!)
+    final processingStatus = widget.file.uploadedFileID != null
+        ? VideoPreviewService.instance
+            .getProcessingStatus(widget.file.uploadedFileID!)
         : null;
 
     final colorScheme = getEnteColorScheme(context);