feat(model-avatar): Update model icon resolution for OpenWebUI

lib/core/utils/model_icon_utils.dart

@@ -1,6 +1,11 @@
 import '../models/model.dart';
 import '../services/api_service.dart';
 
+/// Extracts the profile image URL from a model's metadata.
+/// 
+/// Note: After OpenWebUI updates, the profile_image_url field is stripped from
+/// the /api/models response. This function still checks for legacy data but
+/// clients should use [buildModelAvatarUrl] to construct the proper endpoint URL.
 String? deriveModelIcon(Model? model) {
   if (model == null) return null;
 
@@ -47,6 +52,46 @@ String? deriveModelIcon(Model? model) {
   return null;
 }
 
+/// Builds the model avatar URL using the new OpenWebUI endpoint.
+/// 
+/// OpenWebUI now serves model avatars through a dedicated endpoint:
+/// `/api/v1/models/model/profile/image?id={modelId}`
+/// 
+/// This endpoint:
+/// - Requires authentication
+/// - Handles external URLs (returns 302 redirect)
+/// - Decodes base64 data URIs
+/// - Provides a fallback favicon.png
+String? buildModelAvatarUrl(ApiService? api, String? modelId) {
+  if (api == null || modelId == null || modelId.isEmpty) {
+    return null;
+  }
+
+  final baseUrl = api.baseUrl.trim();
+  if (baseUrl.isEmpty) {
+    return null;
+  }
+
+  try {
+    final baseUri = Uri.parse(baseUrl);
+    final path = '/api/v1/models/model/profile/image';
+    final queryParams = {'id': modelId};
+    
+    final avatarUri = baseUri.replace(
+      path: path,
+      queryParameters: queryParams,
+    );
+    
+    return avatarUri.toString();
+  } catch (_) {
+    // Fallback to manual URL construction
+    final normalizedBase = baseUrl.endsWith('/')
+        ? baseUrl.substring(0, baseUrl.length - 1)
+        : baseUrl;
+    return '$normalizedBase/api/v1/models/model/profile/image?id=${Uri.encodeComponent(modelId)}';
+  }
+}
+
 String? resolveModelIconUrl(ApiService? api, String? rawUrl) {
   final value = rawUrl?.trim();
   if (value == null || value.isEmpty) {
@@ -94,7 +139,30 @@ String? resolveModelIconUrl(ApiService? api, String? rawUrl) {
   }
 }
 
+/// Resolves the final model icon URL for a given model.
+/// 
+/// This function first checks for a legacy profile_image_url in the model's
+/// metadata (for backwards compatibility with older OpenWebUI versions).
+/// If found and it's an external URL or data URI, it uses that directly.
+/// 
+/// Otherwise, it constructs the URL using the new OpenWebUI endpoint:
+/// `/api/v1/models/model/profile/image?id={modelId}`
 String? resolveModelIconUrlForModel(ApiService? api, Model? model) {
-  final raw = deriveModelIcon(model);
-  return resolveModelIconUrl(api, raw);
+  if (model == null) return null;
+
+  // Check for legacy profile_image_url in metadata
+  final legacyUrl = deriveModelIcon(model);
+  
+  // If we have a legacy URL that's external or a data URI, use it directly
+  if (legacyUrl != null && legacyUrl.isNotEmpty) {
+    final trimmed = legacyUrl.trim();
+    if (trimmed.startsWith('data:image') ||
+        trimmed.startsWith('http://') ||
+        trimmed.startsWith('https://')) {
+      return trimmed;
+    }
+  }
+
+  // Use the new dedicated endpoint for model avatars
+  return buildModelAvatarUrl(api, model.id);
 }

lib/shared/widgets/model_avatar.dart

@@ -3,9 +3,31 @@ import 'package:flutter/material.dart';
 import '../theme/theme_extensions.dart';
 import 'user_avatar.dart';
 
+/// Displays a model's avatar image with automatic caching and fallback UI.
+/// 
+/// The avatar can display:
+/// - Network images from the OpenWebUI model avatar endpoint
+/// - Data URIs (base64-encoded images)
+/// - A fallback UI showing the first letter of the model name or a brain icon
+/// 
+/// Images are automatically cached using [CachedNetworkImage] with proper
+/// authentication headers. The cache respects self-signed certificates if
+/// configured.
+/// 
+/// Usage:
+/// ```dart
+/// final avatarUrl = resolveModelIconUrlForModel(apiService, model);
+/// ModelAvatar(size: 40, imageUrl: avatarUrl, label: model.name)
+/// ```
 class ModelAvatar extends StatelessWidget {
+  /// The size (width and height) of the avatar in logical pixels.
   final double size;
+  
+  /// The URL of the avatar image. Should be obtained via
+  /// [resolveModelIconUrlForModel] to use the correct OpenWebUI endpoint.
   final String? imageUrl;
+  
+  /// The model name, used for the fallback UI (shows first letter).
   final String? label;
 
   const ModelAvatar({super.key, required this.size, this.imageUrl, this.label});