fix: make login connection state observable

tauri/src/main.ts

@@ -77,12 +77,32 @@ function normalizeAPIAddress(value: string): string {
 }
 
 function loginFailureMessage(reason: unknown): string {
+  if (reason instanceof Error && reason.message === "LINEUP_LOGIN_TIMEOUT") return "连接 AppServer 超时（10 秒）。请确认 Tailscale 已连接，并核对上方显示的服务地址。";
   if (reason instanceof DOMException && reason.name === "AbortError") return "连接 AppServer 超时（10 秒）。请确认 Tailscale 已连接，且服务地址和端口可访问。";
   const message = reason instanceof Error ? reason.message : "";
   if (message === "Load failed" || message === "Failed to fetch") return "无法连接 AppServer。请确认 Tailscale 已连接，并检查地址是否为 http://100.121.118.116:8090。";
   return message || "登录失败，请稍后重试。";
 }
 
+async function fetchLogin(endpoint: string, phone: string, code: string): Promise<Response> {
+  const controller = new AbortController();
+  let timeoutID = 0;
+  const timeout = new Promise<never>((_, reject) => {
+    timeoutID = window.setTimeout(() => {
+      controller.abort();
+      reject(new Error("LINEUP_LOGIN_TIMEOUT"));
+    }, 10_000);
+  });
+  try {
+    return await Promise.race([
+      fetch(`${endpoint}/login`, { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ phone, code }), signal: controller.signal }),
+      timeout,
+    ]);
+  } finally {
+    window.clearTimeout(timeoutID);
+  }
+}
+
 function appendBubble(role: "human" | "agent", content: string, markdown = false): HTMLElement {
   const row = document.createElement("article"); row.className = `message-row ${role}`;
   if (role === "agent") { const avatar = document.createElement("span"); avatar.className = "message-avatar"; avatar.textContent = "✦"; row.append(avatar); }
@@ -162,19 +182,17 @@ $<HTMLFormElement>("#login-form").addEventListener("submit", async event => {
 
   session.api = endpoint;
   localStorage.setItem("lineup.api", session.api);
-  error.textContent = "正在连接 AppServer…";
+  error.textContent = `正在连接 ${session.api}…`;
   submit.disabled = true;
   submit.textContent = "正在进入…";
-  const controller = new AbortController();
-  const timeout = window.setTimeout(() => controller.abort(), 10_000);
   try {
-    const response = await fetch(api("/login"), { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ phone, code }), signal: controller.signal });
+    const response = await fetchLogin(session.api, phone, code);
     const body = await response.json().catch(() => ({})) as LoginResponse & { error?: string };
     if (!response.ok) throw new Error(body.error || "登录失败");
     session = { ...session, uid: body.uid, agentUID: body.agent_uid || session.agentUID, channelID: body.channel_id || session.channelID, channelType: body.channel_type || session.channelType, lastSeq: 0, active: true };
     loginView.hidden = true; chatView.hidden = false; addSystem("已进入与 AI Agent 的对话"); setPresence("正在同步消息…"); void syncLoop();
   } catch (reason) { error.textContent = loginFailureMessage(reason); }
-  finally { window.clearTimeout(timeout); submit.disabled = false; submit.textContent = "进入 LineUp"; }
+  finally { submit.disabled = false; submit.textContent = "进入 LineUp"; }
 });
 
 $<HTMLFormElement>("#message-form").addEventListener("submit", async event => {