feat: 智能Agent接入前连通性/鉴权校验

- 前端技能市场「接入单个Agent」新增「测试连接」按钮，接入前必须校验通过

- 后端 POST /market/apps/verify-agent：dify 走 chat-messages 鉴权探测(trust_env=False 直连)，n8n/coze 走 HEAD 可达性探测

- upload_app 对 agent 类型做服务端守卫，密钥无效/不可达直接 400 拒绝

- MarketApp 新增 platform 列(dify/n8n/coze)，009 迁移幂等加列

frontend/src/pages/front/MarketPage.tsx

@@ -1172,14 +1172,53 @@ const AgentConnectModal: React.FC<AgentConnectModalProps> = ({ onClose, onConnec
   const [endpoint, setEndpoint] = useState('');
   const [price, setPrice] = useState<number>(0);
   const [connecting, setConnecting] = useState(false);
+  const [verifying, setVerifying] = useState(false);
+  const [verifyMsg, setVerifyMsg] = useState<string>('');
+  const [verifyOk, setVerifyOk] = useState<boolean | null>(null);
 
-  const handleConnect = () => {
+  const runVerify = async (): Promise<boolean | null> => {
+    if (!endpoint.trim() || !apiKey.trim()) {
+      setVerifyMsg('请先填写 API Endpoint 与 API Key');
+      setVerifyOk(false);
+      return false;
+    }
+    setVerifying(true);
+    setVerifyMsg('正在校验连通性与密钥...');
+    setVerifyOk(null);
+    try {
+      const res: any = await marketAPI.verifyAgent({
+        platform,
+        endpoint: endpoint.trim(),
+        api_key: apiKey.trim(),
+      });
+      if (res && res.code === 0 && res.data && res.data.ok) {
+        setVerifyOk(true);
+        setVerifyMsg('✓ ' + (res.data.detail || '校验通过'));
+        return true;
+      }
+      setVerifyOk(false);
+      setVerifyMsg('✗ ' + ((res && res.data && res.data.detail) || '校验未通过'));
+      return false;
+    } catch (e: any) {
+      setVerifyOk(false);
+      setVerifyMsg('✗ 校验请求失败：' + (e?.message || '网络错误'));
+      return false;
+    } finally {
+      setVerifying(false);
+    }
+  };
+
+  const handleConnect = async () => {
     if (!name.trim() || !endpoint.trim() || !apiKey.trim()) return;
+    // 接入前必须先通过连通性 / 鉴权校验
+    const ok = await runVerify();
+    if (!ok) return;
     setConnecting(true);
-    setTimeout(() => {
+    try {
+      await onConnect(platform, { apiKey: apiKey.trim(), endpoint: endpoint.trim() }, price, name.trim(), intro.trim());
+    } finally {
       setConnecting(false);
-      onConnect(platform, { apiKey: apiKey.trim(), endpoint: endpoint.trim() }, price, name.trim(), intro.trim());
-    }, 800);
+    }
   };
 
   return (
@@ -1254,10 +1293,25 @@ const AgentConnectModal: React.FC<AgentConnectModalProps> = ({ onClose, onConnec
             />
             <span className="hub-price-hint">用户对接的 Agent 是否收费由您决定；管理员导入默认免费且审核通过。</span>
           </div>
+          <div className="form-section agent-verify-row">
+            <button
+              type="button"
+              className="form-test-btn"
+              onClick={runVerify}
+              disabled={!endpoint.trim() || !apiKey.trim() || verifying}
+            >
+              {verifying ? '校验中...' : '测试连接'}
+            </button>
+            {verifyMsg && (
+              <span className={`agent-verify-msg ${verifyOk === true ? 'ok' : verifyOk === false ? 'err' : ''}`}>
+                {verifyMsg}
+              </span>
+            )}
+          </div>
           <button
             className="form-submit-btn"
             onClick={handleConnect}
-            disabled={!name.trim() || !endpoint.trim() || !apiKey.trim() || connecting}
+            disabled={!name.trim() || !endpoint.trim() || !apiKey.trim() || connecting || verifying}
           >
             {connecting ? '接入中...' : '接入 Agent'}
           </button>
@@ -1393,6 +1447,7 @@ const MarketPage: React.FC = () => {
         source: 'user',
         agent_endpoint: config.endpoint || '',
         api_key: config.apiKey || '',
+        platform: platformId || 'dify',
       });
       // 重新加载列表
       loadApps();