优化聊天框输入聚焦逻辑，增强网络错误处理

src/components/chat/GlobalChatbox.tsx

@@ -113,6 +113,7 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
   const [conversationId, setConversationId] = useState<string | undefined>(undefined);
   const abortRef = useRef<AbortController | null>(null);
   const bottomRef = useRef<HTMLDivElement>(null);
+  const inputRef = useRef<HTMLInputElement | null>(null);
   const theme = useTheme();
 
   const canSend = useMemo(() => input.trim().length > 0 && !isStreaming, [input, isStreaming]);
@@ -122,6 +123,14 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
     bottomRef.current?.scrollIntoView({ behavior: "smooth" });
   }, [messages, isStreaming]);
 
+  useEffect(() => {
+    if (!open) return;
+    const timer = window.setTimeout(() => {
+      inputRef.current?.focus();
+    }, 0);
+    return () => window.clearTimeout(timer);
+  }, [open]);
+
   const handleSend = async () => {
     const prompt = input.trim();
     if (!prompt || isStreaming) return;
@@ -443,6 +452,7 @@ export const GlobalChatbox: React.FC<Props> = ({ open, onClose }) => {
                 }}
             >
                 <TextField
+                inputRef={inputRef}
                 value={input}
                 onChange={(e) => setInput(e.target.value)}
                 onKeyDown={(e) => {

src/lib/chatStream.test.ts

@@ -97,4 +97,18 @@ describe("streamCopilotChat", () => {
       { type: "error", message: "Login expired. Please sign in again.", detail: undefined },
     ]);
   });
+
+  it("emits network error when fetch throws", async () => {
+    apiFetch.mockRejectedValue(new TypeError("Failed to fetch"));
+
+    const events: Array<{ type: string; message?: string; detail?: string }> = [];
+    await streamCopilotChat({
+      message: "hi",
+      onEvent: (event) => events.push(event),
+    });
+
+    expect(events).toEqual([
+      { type: "error", message: "network request failed", detail: "Failed to fetch" },
+    ]);
+  });
 });

src/lib/chatStream.ts

@@ -38,7 +38,9 @@ export const streamCopilotChat = async ({
   signal,
   onEvent,
 }: StreamOptions) => {
-  const response = await apiFetch(`${config.BACKEND_URL}/api/v1/copilot/chat/stream`, {
+  let response: Response;
+  try {
+    response = await apiFetch(`${config.BACKEND_URL}/api/v1/copilot/chat/stream`, {
       method: "POST",
       signal,
       headers: {
@@ -51,6 +53,15 @@ export const streamCopilotChat = async ({
       }),
       skipAuthRedirect: true,
     });
+  } catch (error) {
+    const detail = error instanceof Error ? error.message : String(error);
+    onEvent({
+      type: "error",
+      message: "network request failed",
+      detail,
+    });
+    return;
+  }
 
   if (!response.ok || !response.body) {
     const detail = await response.text();