feat(chat): add support for custom HTTP headers in image attachments

lib/features/chat/widgets/assistant_message_widget.dart

@@ -1063,6 +1063,7 @@ class _AssistantMessageWidgetState extends ConsumerState<AssistantMessageWidget>
                     ),
                     disableAnimation:
                         false, // Keep animations enabled to prevent black display
+                    httpHeaders: _headersForFile(imageFiles[0]),
                   );
                 },
               ),
@@ -1087,12 +1088,31 @@ class _AssistantMessageWidgetState extends ConsumerState<AssistantMessageWidget>
                   ),
                   disableAnimation:
                       false, // Keep animations enabled to prevent black display
+                  httpHeaders: _headersForFile(file),
                 );
               }).toList(),
             ),
     );
   }
 
+  Map<String, String>? _headersForFile(dynamic file) {
+    if (file is! Map) return null;
+    final rawHeaders = file['headers'];
+    if (rawHeaders is! Map) return null;
+    final result = <String, String>{};
+    rawHeaders.forEach((key, value) {
+      final keyString = key?.toString();
+      final valueString = value?.toString();
+      if (keyString != null &&
+          keyString.isNotEmpty &&
+          valueString != null &&
+          valueString.isNotEmpty) {
+        result[keyString] = valueString;
+      }
+    });
+    return result.isEmpty ? null : result;
+  }
+
   Widget _buildNonImageFiles(List<dynamic> nonImageFiles) {
     return Wrap(
       spacing: Spacing.sm,

lib/features/chat/widgets/enhanced_image_attachment.dart

@@ -51,7 +51,9 @@ bool _isSvgUrl(String url) {
 
   // Check for .svg file extension (with or without query string)
   final queryIndex = lowerUrl.indexOf('?');
-  final pathPart = queryIndex >= 0 ? lowerUrl.substring(0, queryIndex) : lowerUrl;
+  final pathPart = queryIndex >= 0
+      ? lowerUrl.substring(0, queryIndex)
+      : lowerUrl;
   if (pathPart.endsWith('.svg')) return true;
 
   // Check for SVG MIME type in query parameters only (not in path)
@@ -75,6 +77,17 @@ bool _isSvgBytes(Uint8List bytes) {
   return header.toLowerCase().contains('<svg');
 }
 
+Map<String, String>? _mergeHeaders(
+  Map<String, String>? defaults,
+  Map<String, String>? overrides,
+) {
+  if ((defaults == null || defaults.isEmpty) &&
+      (overrides == null || overrides.isEmpty)) {
+    return null;
+  }
+  return {...?defaults, ...?overrides};
+}
+
 class EnhancedImageAttachment extends ConsumerStatefulWidget {
   final String attachmentId;
   final bool isMarkdownFormat;
@@ -82,6 +95,7 @@ class EnhancedImageAttachment extends ConsumerStatefulWidget {
   final BoxConstraints? constraints;
   final bool isUserMessage;
   final bool disableAnimation;
+  final Map<String, String>? httpHeaders;
 
   const EnhancedImageAttachment({
     super.key,
@@ -91,6 +105,7 @@ class EnhancedImageAttachment extends ConsumerStatefulWidget {
     this.constraints,
     this.isUserMessage = false,
     this.disableAnimation = false,
+    this.httpHeaders,
   });
 
   @override
@@ -483,7 +498,8 @@ class _EnhancedImageAttachmentState
 
   Widget _buildNetworkImage() {
     // Get authentication headers if available
-    final headers = buildImageHeadersFromWidgetRef(ref);
+    final defaultHeaders = buildImageHeadersFromWidgetRef(ref);
+    final headers = _mergeHeaders(defaultHeaders, widget.httpHeaders);
 
     final cacheManager = ref.watch(selfSignedImageCacheManagerProvider);
     final imageWidget = CachedNetworkImage(
@@ -516,7 +532,8 @@ class _EnhancedImageAttachmentState
 
   Widget _buildNetworkSvg() {
     // Get authentication headers if available
-    final headers = buildImageHeadersFromWidgetRef(ref);
+    final defaultHeaders = buildImageHeadersFromWidgetRef(ref);
+    final headers = _mergeHeaders(defaultHeaders, widget.httpHeaders);
 
     final svgWidget = SvgPicture.network(
       _cachedImageData!,
@@ -647,6 +664,7 @@ class _EnhancedImageAttachmentState
           imageData: _cachedImageData!,
           tag: _heroTag,
           isSvg: _isSvg,
+          customHeaders: widget.httpHeaders,
         ),
       ),
     );
@@ -657,12 +675,14 @@ class FullScreenImageViewer extends ConsumerWidget {
   final String imageData;
   final String tag;
   final bool isSvg;
+  final Map<String, String>? customHeaders;
 
   const FullScreenImageViewer({
     super.key,
     required this.imageData,
     required this.tag,
     this.isSvg = false,
+    this.customHeaders,
   });
 
   @override
@@ -671,7 +691,8 @@ class FullScreenImageViewer extends ConsumerWidget {
 
     if (imageData.startsWith('http')) {
       // Get authentication headers if available
-      final headers = buildImageHeadersFromWidgetRef(ref);
+      final defaultHeaders = buildImageHeadersFromWidgetRef(ref);
+      final headers = _mergeHeaders(defaultHeaders, customHeaders);
 
       if (isSvg || _isSvgUrl(imageData)) {
         imageWidget = SvgPicture.network(
@@ -818,13 +839,14 @@ class FullScreenImageViewer extends ConsumerWidget {
         if (api != null && api.serverConfig.customHeaders.isNotEmpty) {
           headers.addAll(api.serverConfig.customHeaders);
         }
+        final mergedHeaders = _mergeHeaders(headers, customHeaders);
 
         final client = api?.dio ?? dio.Dio();
         final response = await client.get<List<int>>(
           imageData,
           options: dio.Options(
             responseType: dio.ResponseType.bytes,
-            headers: headers.isNotEmpty ? headers : null,
+            headers: mergedHeaders,
           ),
         );
         final data = response.data;

lib/features/chat/widgets/user_message_bubble.dart

@@ -150,6 +150,7 @@ class _UserMessageBubbleState extends ConsumerState<UserMessageBubble> {
                   maxHeight: 350,
                 ),
                 disableAnimation: widget.isStreaming,
+                httpHeaders: _headersForFile(imageFiles[0]),
               ),
             ),
           ),
@@ -191,6 +192,7 @@ class _UserMessageBubbleState extends ConsumerState<UserMessageBubble> {
                           maxHeight: 180,
                         ),
                         disableAnimation: widget.isStreaming,
+                        httpHeaders: _headersForFile(entry.value),
                       ),
                     ),
                   ),
@@ -232,6 +234,7 @@ class _UserMessageBubbleState extends ConsumerState<UserMessageBubble> {
                           maxHeight: imageCount == 3 ? 135 : 90,
                         ),
                         disableAnimation: widget.isStreaming,
+                        httpHeaders: _headersForFile(file),
                       ),
                     ),
                   );
@@ -401,6 +404,24 @@ class _UserMessageBubbleState extends ConsumerState<UserMessageBubble> {
     );
   }
 
+  Map<String, String>? _headersForFile(dynamic file) {
+    if (file is! Map) return null;
+    final rawHeaders = file['headers'];
+    if (rawHeaders is! Map) return null;
+    final result = <String, String>{};
+    rawHeaders.forEach((key, value) {
+      final keyString = key?.toString();
+      final valueString = value?.toString();
+      if (keyString != null &&
+          keyString.isNotEmpty &&
+          valueString != null &&
+          valueString.isNotEmpty) {
+        result[keyString] = valueString;
+      }
+    });
+    return result.isEmpty ? null : result;
+  }
+
   // Assistant-only helpers removed; this widget renders only user bubbles.
 
   @override