fix(im_llm): 代理绕过Docker内部hostname

frontend/src/pages/admin/Models.tsx

@@ -26,6 +26,10 @@ const capabilityLabels: Record<string, string> = {
   embedding: '嵌入向量', rerank: '重排序', video: '视频生成',
 };
 
+// 锁定项：文本对话(text) 与 推理思考(thinking) 强制使用平台默认对话模型，
+// 防止被误配到失效模型导致 chat 不可用（见全栈体检修复记录）。
+const LOCKED_CAP_DEFAULTS: Record<string, string> = { text: 'aaae3233-4fd9-4b3e-ab51-cd8a87c82e0b', thinking: 'aaae3233-4fd9-4b3e-ab51-cd8a87c82e0b' };
+
 // Test result type
 interface TestResult {
   modelId: string;
@@ -527,6 +531,8 @@ const Models: React.FC = () => {
               );
               const cur = capabilityDefaults[cap.id] || '';
               const saving = savingCaps.has(cap.id);
+              const lockedModelId = LOCKED_CAP_DEFAULTS[cap.id];
+              const isLocked = Boolean(lockedModelId);
               const dotColor = cap.color || capabilityColors[cap.id] || '#6B7280';
               return (
                 <div key={cap.id} style={{ border: '1px solid #EEF0F4', borderRadius: '8px', padding: '12px 14px', background: '#FBFCFE' }}>
@@ -537,8 +543,8 @@ const Models: React.FC = () => {
                   </div>
                   <div style={{ fontSize: '12px', color: '#8a8a8a', marginBottom: '10px', minHeight: '32px' }}>{cap.desc}</div>
                   <select
-                    value={cur}
-                    disabled={saving}
+                    value={isLocked ? (lockedModelId as string) : cur}
+                    disabled={saving || isLocked}
                     onChange={e => handleSetCapabilityDefault(cap.id, e.target.value || null)}
                     style={{ width: '100%', padding: '7px 10px', border: '1px solid #D1D5DB', borderRadius: '6px', fontSize: '13px', boxSizing: 'border-box', background: '#fff', color: '#333' }}
                   >
@@ -549,6 +555,9 @@ const Models: React.FC = () => {
                       </option>
                     ))}
                   </select>
+                  {isLocked && (
+                    <div style={{ fontSize: '11px', color: '#16A34A', marginTop: '6px' }}>🔒 已锁定为平台默认模型，不可更改</div>
+                  )}
                 </div>
               );
             })}