fix(ui): 5 项 E2E 测试 Bug 修复 — Agent 502 / 错误持久化 / 模型标记 / 侧面板 / 记忆页

- BUG-01: createFromTemplate 在 saas-relay 模式下 try-catch 跳过本地 Kernel
- BUG-02: upsertActiveConversation 持久化前剥离 error/streaming/optimistic 字段
- BUG-04: ModelSelector 添加 available 标记，ChatArea 追踪失败模型 ID
- BUG-05: VikingPanel 移除 status?.available 门控，不可用时 disabled + 重连按钮
- BUG-06: 侧面板 tooltip 改为"查看产物文件"，空状态增加图标和说明

desktop/src/components/ChatArea.tsx

@@ -72,13 +72,27 @@ export function ChatArea({ compact, onOpenDetail }: { compact?: boolean; onOpenD
   const saasModels = useSaaSStore((s) => s.availableModels);
   const isLoggedIn = useSaaSStore((s) => s.isLoggedIn);
 
+  // Track models that failed with API key errors in this session
+  const failedModelIds = useRef<Set<string>>(new Set());
+
+  // Scan messages for API key errors to populate failedModelIds
+  useEffect(() => {
+    for (const msg of messages) {
+      if (msg.error && (msg.error.includes('没有可用的 API Key') || msg.error.includes('Key Pool'))) {
+        failedModelIds.current.add(currentModel);
+      }
+    }
+  }, [messages, currentModel]);
+
   // Merge models: SaaS available models take priority when logged in
   const models = useMemo(() => {
+    const failed = failedModelIds.current;
     if (isLoggedIn && saasModels.length > 0) {
       return saasModels.map(m => ({
         id: m.alias || m.id,
         name: m.alias || m.id,
         provider: m.provider_id,
+        available: !failed.has(m.alias || m.id),
       }));
     }
     if (configModels.length > 0) {