feat: 补全模型能力选项(11种) + 按能力指定默认模型 + Auto自动模式

frontend/src/pages/front/ChatPage.tsx

@@ -338,8 +338,9 @@ const ChatPage: React.FC = () => {
       const data = res.data || res;
       const models = Array.isArray(data) ? data : (data?.items || []);
       setChatModels(models);
-      if (models.length > 0 && !selectedModelId) {
-        setSelectedModelId(models[0].id);
+      // 全平台默认使用 Auto（按能力自动匹配平台默认模型）
+      if (!selectedModelId) {
+        setSelectedModelId('auto');
       }
     }).catch(() => {
       setChatModels([]);
@@ -463,8 +464,11 @@ const ChatPage: React.FC = () => {
     return [...pinned.filter(c => c.title.toLowerCase().includes(q)), ...unpinned.filter(c => c.title.toLowerCase().includes(q))];
   }, [conversations, searchQuery]);
 
-  // Selected model info
-  const selectedModel = chatModels.find(m => m.id === selectedModelId) || chatModels[0] || { id: '', name: '选择模型', status: 'free', provider_name: '' };
+  // Selected model info（Auto 为按能力自动匹配平台默认模型）
+  const AUTO_MODEL = { id: 'auto', name: 'Auto 自动', display_name: 'Auto 自动', status: 'free', provider_name: '按能力匹配', price_per_million_tokens: 0, capabilities: [] as string[] };
+  const selectedModel = selectedModelId === 'auto'
+    ? AUTO_MODEL
+    : (chatModels.find(m => m.id === selectedModelId) || chatModels[0] || AUTO_MODEL);
 
   // Scroll to bottom when messages change
   useEffect(() => {
@@ -792,6 +796,18 @@ const ChatPage: React.FC = () => {
                     </div>
                   }
                 >
+                  {/* Auto 自动匹配（默认） */}
+                  <button
+                    key="auto"
+                    className={`dropdown-item ${selectedModelId === 'auto' ? 'selected' : ''}`}
+                    onClick={() => setSelectedModelId('auto')}
+                  >
+                    <div className="model-dropdown-item">
+                      <span>⚡ Auto 自动</span>
+                      <span className="model-provider-tag">按能力匹配默认模型</span>
+                      <span className="model-cap-badge">默认</span>
+                    </div>
+                  </button>
                   {chatModels.filter(m => m.is_enabled !== false).map(model => (
                     <button
                       key={model.id}