feat: track byte-level download progress for extension downloads

Pass active download item ID through extension download pipeline so
fileDownload can report bytes received/total via ItemProgressWriter.
Add bytesTotal field to DownloadItem model and show X/Y MB progress
in queue tab when total size is known.

lib/models/download_item.dart

@@ -12,13 +12,7 @@ enum DownloadStatus {
   skipped,
 }
 
-enum DownloadErrorType {
-  unknown,
-  notFound,
-  rateLimit,
-  network,
-  permission,
-}
+enum DownloadErrorType { unknown, notFound, rateLimit, network, permission }
 
 @JsonSerializable()
 class DownloadItem {
@@ -28,7 +22,8 @@ class DownloadItem {
   final DownloadStatus status;
   final double progress;
   final double speedMBps;
-  final int bytesReceived; // Bytes downloaded so far (for unknown size downloads)
+  final int bytesReceived; // Bytes downloaded so far
+  final int bytesTotal; // Total bytes when the server provides content length
   final String? filePath;
   final String? error;
   final DownloadErrorType? errorType;
@@ -44,6 +39,7 @@ class DownloadItem {
     this.progress = 0.0,
     this.speedMBps = 0.0,
     this.bytesReceived = 0,
+    this.bytesTotal = 0,
     this.filePath,
     this.error,
     this.errorType,
@@ -60,6 +56,7 @@ class DownloadItem {
     double? progress,
     double? speedMBps,
     int? bytesReceived,
+    int? bytesTotal,
     String? filePath,
     String? error,
     DownloadErrorType? errorType,
@@ -75,6 +72,7 @@ class DownloadItem {
       progress: progress ?? this.progress,
       speedMBps: speedMBps ?? this.speedMBps,
       bytesReceived: bytesReceived ?? this.bytesReceived,
+      bytesTotal: bytesTotal ?? this.bytesTotal,
       filePath: filePath ?? this.filePath,
       error: error ?? this.error,
       errorType: errorType ?? this.errorType,
@@ -86,7 +84,7 @@ class DownloadItem {
 
   String get errorMessage {
     if (error == null) return '';
-    
+
     switch (errorType) {
       case DownloadErrorType.notFound:
         return 'Song not found on any service';

lib/models/download_item.g.dart

@@ -16,6 +16,7 @@ DownloadItem _$DownloadItemFromJson(Map<String, dynamic> json) => DownloadItem(
   progress: (json['progress'] as num?)?.toDouble() ?? 0.0,
   speedMBps: (json['speedMBps'] as num?)?.toDouble() ?? 0.0,
   bytesReceived: (json['bytesReceived'] as num?)?.toInt() ?? 0,
+  bytesTotal: (json['bytesTotal'] as num?)?.toInt() ?? 0,
   filePath: json['filePath'] as String?,
   error: json['error'] as String?,
   errorType: $enumDecodeNullable(_$DownloadErrorTypeEnumMap, json['errorType']),
@@ -33,6 +34,7 @@ Map<String, dynamic> _$DownloadItemToJson(DownloadItem instance) =>
       'progress': instance.progress,
       'speedMBps': instance.speedMBps,
       'bytesReceived': instance.bytesReceived,
+      'bytesTotal': instance.bytesTotal,
       'filePath': instance.filePath,
       'error': instance.error,
       'errorType': _$DownloadErrorTypeEnumMap[instance.errorType],

lib/providers/download_queue_provider.dart

@@ -1166,12 +1166,14 @@ class _ProgressUpdate {
   final double progress;
   final double? speedMBps;
   final int? bytesReceived;
+  final int? bytesTotal;
 
   const _ProgressUpdate({
     required this.status,
     required this.progress,
     this.speedMBps,
     this.bytesReceived,
+    this.bytesTotal,
   });
 }
 
@@ -1587,6 +1589,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           progress: normalizedProgress,
           speedMBps: normalizedSpeed,
           bytesReceived: normalizedBytes,
+          bytesTotal: bytesTotal,
         );
 
         if (LogBuffer.loggingEnabled) {
@@ -1624,11 +1627,13 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
           progress: update.progress,
           speedMBps: update.speedMBps ?? current.speedMBps,
           bytesReceived: update.bytesReceived ?? current.bytesReceived,
+          bytesTotal: update.bytesTotal ?? current.bytesTotal,
         );
         if (current.status != next.status ||
             current.progress != next.progress ||
             current.speedMBps != next.speedMBps ||
-            current.bytesReceived != next.bytesReceived) {
+            current.bytesReceived != next.bytesReceived ||
+            current.bytesTotal != next.bytesTotal) {
           if (!changed) {
             updatedItems = List<DownloadItem>.from(updatedItems);
             changed = true;
@@ -2408,6 +2413,7 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
             progress: 0,
             speedMBps: 0,
             bytesReceived: 0,
+            bytesTotal: 0,
           );
         })
         .toList(growable: false);

lib/screens/queue_tab.dart

@@ -5537,17 +5537,29 @@ class _QueueTabState extends ConsumerState<QueueTab> {
                               ),
                               const SizedBox(width: 8),
                               Text(
-                                // When progress is 0 (unknown size, e.g. YouTube tunnel mode),
-                                // show bytes downloaded instead of percentage
-                                item.progress > 0
-                                    ? (item.speedMBps > 0
-                                          ? '${(item.progress * 100).toStringAsFixed(0)}% • ${item.speedMBps.toStringAsFixed(1)} MB/s'
-                                          : '${(item.progress * 100).toStringAsFixed(0)}%')
+                                item.bytesTotal > 0 && item.bytesReceived > 0
+                                    ? (() {
+                                        final receivedMB =
+                                            item.bytesReceived / (1024 * 1024);
+                                        final totalMB =
+                                            item.bytesTotal / (1024 * 1024);
+                                        final progressLabel = item.progress > 0
+                                            ? '${(item.progress * 100).toStringAsFixed(0)}% • '
+                                            : '';
+                                        final speedLabel = item.speedMBps > 0
+                                            ? ' • ${item.speedMBps.toStringAsFixed(1)} MB/s'
+                                            : '';
+                                        return '$progressLabel${receivedMB.toStringAsFixed(1)} / ${totalMB.toStringAsFixed(1)} MB$speedLabel';
+                                      })()
                                     : (item.bytesReceived > 0
-                                          ? '${(item.bytesReceived / (1024 * 1024)).toStringAsFixed(1)} MB • ${item.speedMBps.toStringAsFixed(1)} MB/s'
-                                          : (item.speedMBps > 0
-                                                ? 'Downloading • ${item.speedMBps.toStringAsFixed(1)} MB/s'
-                                                : 'Starting...')),
+                                          ? '${(item.bytesReceived / (1024 * 1024)).toStringAsFixed(1)} MB${item.speedMBps > 0 ? ' • ${item.speedMBps.toStringAsFixed(1)} MB/s' : ''}'
+                                          : (item.progress > 0
+                                                ? (item.speedMBps > 0
+                                                      ? '${(item.progress * 100).toStringAsFixed(0)}% • ${item.speedMBps.toStringAsFixed(1)} MB/s'
+                                                      : '${(item.progress * 100).toStringAsFixed(0)}%')
+                                                : (item.speedMBps > 0
+                                                      ? 'Downloading • ${item.speedMBps.toStringAsFixed(1)} MB/s'
+                                                      : 'Starting...'))),
                                 style: Theme.of(context).textTheme.labelSmall
                                     ?.copyWith(
                                       color: colorScheme.primary,