Add file metadata display in viewer and upload progress snackbar

- Backend: Add modified_by column to files table
- Backend: Track who modified files via WOPI PutFile
- Backend: Return fileInfo (name, size, lastModified, modifiedByName) in view response
- Flutter: Update DocumentCapabilities model with FileInfo
- Flutter: Display actual last modified date and user in document viewer
- Flutter: Show upload progress snackbar with percentage that auto-dismisses on completion

b0esche_cloud/lib/blocs/document_viewer/document_viewer_state.dart

@@ -26,7 +26,12 @@ class DocumentViewerReady extends DocumentViewerState {
   });
 
   @override
-  List<Object> get props => [viewUrl, caps, token, if (fileInfo != null) fileInfo!];
+  List<Object> get props => [
+    viewUrl,
+    caps,
+    token,
+    if (fileInfo != null) fileInfo!,
+  ];
 }
 
 class DocumentViewerError extends DocumentViewerState {

b0esche_cloud/lib/models/document_capabilities.dart

@@ -20,8 +20,8 @@ class FileInfo extends Equatable {
     return FileInfo(
       name: json['name'] ?? '',
       size: json['size'] ?? 0,
-      lastModified: json['lastModified'] != null 
-          ? DateTime.tryParse(json['lastModified']) 
+      lastModified: json['lastModified'] != null
+          ? DateTime.tryParse(json['lastModified'])
           : null,
       modifiedByName: json['modifiedByName'],
     );

b0esche_cloud/lib/models/viewer_session.dart

@@ -17,7 +17,13 @@ class ViewerSession extends Equatable {
   });
 
   @override
-  List<Object?> get props => [viewUrl, capabilities, token, expiresAt, fileInfo];
+  List<Object?> get props => [
+    viewUrl,
+    capabilities,
+    token,
+    expiresAt,
+    fileInfo,
+  ];
 
   factory ViewerSession.fromJson(Map<String, dynamic> json) {
     return ViewerSession(
@@ -25,7 +31,9 @@ class ViewerSession extends Equatable {
       capabilities: DocumentCapabilities.fromJson(json['capabilities']),
       token: json['token'],
       expiresAt: DateTime.parse(json['expiresAt']),
-      fileInfo: json['fileInfo'] != null ? FileInfo.fromJson(json['fileInfo']) : null,
+      fileInfo: json['fileInfo'] != null
+          ? FileInfo.fromJson(json['fileInfo'])
+          : null,
     );
   }
 }

b0esche_cloud/lib/pages/document_viewer.dart

@@ -118,9 +118,11 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
                   final modifiedDate = fileInfo.lastModified;
                   final modifiedBy = fileInfo.modifiedByName;
                   if (modifiedDate != null) {
-                    final formattedDate = '${modifiedDate.day.toString().padLeft(2, '0')}.${modifiedDate.month.toString().padLeft(2, '0')}.${modifiedDate.year} ${modifiedDate.hour.toString().padLeft(2, '0')}:${modifiedDate.minute.toString().padLeft(2, '0')}';
+                    final formattedDate =
+                        '${modifiedDate.day.toString().padLeft(2, '0')}.${modifiedDate.month.toString().padLeft(2, '0')}.${modifiedDate.year} ${modifiedDate.hour.toString().padLeft(2, '0')}:${modifiedDate.minute.toString().padLeft(2, '0')}';
                     if (modifiedBy != null && modifiedBy.isNotEmpty) {
-                      lastModifiedText = 'Last modified: $formattedDate by $modifiedBy';
+                      lastModifiedText =
+                          'Last modified: $formattedDate by $modifiedBy';
                     } else {
                       lastModifiedText = 'Last modified: $formattedDate';
                     }
@@ -581,9 +583,11 @@ class _DocumentViewerState extends State<DocumentViewer> {
                     final modifiedDate = fileInfo.lastModified;
                     final modifiedBy = fileInfo.modifiedByName;
                     if (modifiedDate != null) {
-                      final formattedDate = '${modifiedDate.day.toString().padLeft(2, '0')}.${modifiedDate.month.toString().padLeft(2, '0')}.${modifiedDate.year} ${modifiedDate.hour.toString().padLeft(2, '0')}:${modifiedDate.minute.toString().padLeft(2, '0')}';
+                      final formattedDate =
+                          '${modifiedDate.day.toString().padLeft(2, '0')}.${modifiedDate.month.toString().padLeft(2, '0')}.${modifiedDate.year} ${modifiedDate.hour.toString().padLeft(2, '0')}:${modifiedDate.minute.toString().padLeft(2, '0')}';
                       if (modifiedBy != null && modifiedBy.isNotEmpty) {
-                        lastModifiedText = 'Last modified: $formattedDate by $modifiedBy';
+                        lastModifiedText =
+                            'Last modified: $formattedDate by $modifiedBy';
                       } else {
                         lastModifiedText = 'Last modified: $formattedDate';
                       }

b0esche_cloud/lib/pages/file_explorer.dart

@@ -37,6 +37,7 @@ class _FileExplorerState extends State<FileExplorer> {
   final TextEditingController _searchController = TextEditingController();
   String _searchQuery = '';
   final Map<String, bool> _hovered = {};
+  ScaffoldFeatureController<SnackBar, SnackBarClosedReason>? _uploadSnackBarController;
 
   String _getParentPath(String path) {
     if (path == '/') return '/';
@@ -684,16 +685,63 @@ class _FileExplorerState extends State<FileExplorer> {
     return BlocListener<UploadBloc, UploadState>(
       listener: (context, uploadState) {
         if (uploadState is UploadInProgress) {
+          // Calculate overall progress
+          final uploads = uploadState.uploads;
+          final activeUploads = uploads.where((u) => !u.isCompleted && u.error == null).toList();
+          final completedUploads = uploads.where((u) => u.isCompleted).toList();
+          
           // Show error if any upload failed
-          for (final upload in uploadState.uploads) {
+          for (final upload in uploads) {
             if (upload.error != null && upload.error!.isNotEmpty) {
               ScaffoldMessenger.of(context).showSnackBar(
                 SnackBar(content: Text('Upload failed: ${upload.error}')),
               );
             }
           }
-          final hasCompleted = uploadState.uploads.any((u) => u.isCompleted);
-          if (hasCompleted) {
+          
+          // Show progress snackbar for active uploads
+          if (activeUploads.isNotEmpty) {
+            final totalProgress = uploads.fold<double>(0, (sum, u) => sum + u.progress) / uploads.length;
+            final fileName = activeUploads.length == 1 
+                ? activeUploads.first.fileName 
+                : '${activeUploads.length} files';
+            
+            // Dismiss previous snackbar and show new one
+            _uploadSnackBarController?.close();
+            _uploadSnackBarController = ScaffoldMessenger.of(context).showSnackBar(
+              SnackBar(
+                content: Row(
+                  children: [
+                    SizedBox(
+                      width: 20,
+                      height: 20,
+                      child: CircularProgressIndicator(
+                        value: totalProgress,
+                        strokeWidth: 2,
+                        color: Colors.white,
+                        backgroundColor: Colors.white24,
+                      ),
+                    ),
+                    const SizedBox(width: 12),
+                    Expanded(
+                      child: Text(
+                        'Uploading $fileName... ${(totalProgress * 100).toInt()}%',
+                        overflow: TextOverflow.ellipsis,
+                      ),
+                    ),
+                  ],
+                ),
+                duration: const Duration(days: 1), // Keep showing until dismissed
+                backgroundColor: AppTheme.surfaceColor,
+              ),
+            );
+          }
+          
+          // Dismiss snackbar and refresh when all uploads complete
+          if (completedUploads.length == uploads.length && uploads.isNotEmpty) {
+            _uploadSnackBarController?.close();
+            _uploadSnackBarController = null;
+            
             final fbState = context.read<FileBrowserBloc>().state;
             String currentPath = '/';
             if (fbState is DirectoryLoaded) currentPath = fbState.currentPath;
@@ -702,6 +750,10 @@ class _FileExplorerState extends State<FileExplorer> {
               LoadDirectory(orgId: widget.orgId, path: currentPath),
             );
           }
+        } else if (uploadState is UploadInitial) {
+          // Upload finished or reset - dismiss snackbar
+          _uploadSnackBarController?.close();
+          _uploadSnackBarController = null;
         }
       },
       child: BlocBuilder<FileBrowserBloc, FileBrowserState>(