feat: detect silently-lapsed login state and alert the user

src/main.ts

@@ -165,6 +165,37 @@ function openFile(filePath: string): void {
   }
 }
 
+/**
+ * Pop an out-of-band desktop notification. Used when the login state lapses —
+ * WeChat itself is the dead channel, so we cannot reach the user through it.
+ * Best-effort: silently no-ops if the platform mechanism is unavailable.
+ */
+function notifyDesktop(title: string, message: string): void {
+  const platform = process.platform;
+  try {
+    if (platform === 'win32') {
+      const safe = (v: string) => v.replace(/'/g, "''");
+      const ps = [
+        `[Windows.UI.Notifications.ToastNotificationManager, Windows.UI.Notifications, ContentType = WindowsRuntime] > $null;`,
+        `$t = [Windows.UI.Notifications.ToastNotificationManager]::GetTemplateContent([Windows.UI.Notifications.ToastTemplateType]::ToastText02);`,
+        `$x = $t.GetElementsByTagName('text');`,
+        `$x.Item(0).AppendChild($t.CreateTextNode('${safe(title)}')) > $null;`,
+        `$x.Item(1).AppendChild($t.CreateTextNode('${safe(message)}')) > $null;`,
+        `$n = [Windows.UI.Notifications.ToastNotification]::new($t);`,
+        `[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier('wechat-claude-code').Show($n);`,
+      ].join(' ');
+      spawnSync('powershell', ['-NoProfile', '-Command', ps], { stdio: 'ignore' });
+    } else if (platform === 'darwin') {
+      const safe = (v: string) => v.replace(/"/g, '\\"');
+      spawnSync('osascript', ['-e', `display notification "${safe(message)}" with title "${safe(title)}"`], { stdio: 'ignore' });
+    } else {
+      spawnSync('notify-send', [title, message], { stdio: 'ignore' });
+    }
+  } catch (err) {
+    logger.warn('Desktop notification failed', { error: err instanceof Error ? err.message : String(err) });
+  }
+}
+
 // ---------------------------------------------------------------------------
 // Setup
 // ---------------------------------------------------------------------------
@@ -315,6 +346,11 @@ async function runDaemon(): Promise<void> {
       logger.warn('Session expired, will keep retrying...');
       console.error('⚠️ 微信会话已过期，请重新运行 setup 扫码绑定');
     },
+    onSessionLikelyExpired: () => {
+      logger.warn('Login state likely expired — notifying user out-of-band');
+      console.error('⚠️ 微信登录态可能已失效，收不到新消息。请重新扫码：node dist/main.js setup 然后 npm run daemon -- restart');
+      notifyDesktop('WeChat Claude Code', '微信登录态可能已过期，请重新扫码绑定。');
+    },
   };
 
   const monitor = createMonitor(api, callbacks);

src/wechat/monitor.ts

@@ -9,9 +9,26 @@ const BACKOFF_THRESHOLD = 3;
 const BACKOFF_LONG_MS = 30_000;
 const BACKOFF_SHORT_MS = 3_000;
 
+// Heuristic detection of a silently-lapsed login state.
+//
+// The ilink bot login state can expire without any error code (typically
+// overnight): the token still authenticates and getUpdates keeps returning
+// HTTP 200, but the server stops delivering messages. A/B comparing a valid
+// vs. an expired token showed the only reliable difference in that state:
+//   healthy idle : msgs === []    AND get_updates_buf is a non-empty string
+//   expired      : msgs is ABSENT AND get_updates_buf is empty/missing
+// (ret is undefined in both cases, so ret cannot be used to tell them apart.)
+//
+// We require several consecutive expired-shaped responses before alerting so a
+// one-off network blip never trips it. A genuinely idle-but-healthy session
+// always carries a fresh buf, so quiet nights do not false-positive.
+const EXPIRED_SHAPE_THRESHOLD = 3;
+
 export interface MonitorCallbacks {
   onMessage: (msg: WeixinMessage) => Promise<void>;
   onSessionExpired: () => void;
+  /** Fired once when the login state appears to have silently lapsed. */
+  onSessionLikelyExpired?: () => void;
 }
 
 export function createMonitor(api: WeChatApi, callbacks: MonitorCallbacks) {
@@ -22,6 +39,8 @@ export function createMonitor(api: WeChatApi, callbacks: MonitorCallbacks) {
 
   async function run(): Promise<void> {
     let consecutiveFailures = 0;
+    let expiredShapeStreak = 0;
+    let expiryAlerted = false;
 
     while (!controller.signal.aborted) {
       try {
@@ -42,6 +61,25 @@ export function createMonitor(api: WeChatApi, callbacks: MonitorCallbacks) {
           logger.warn('getUpdates returned error', { ret: resp.ret, retmsg: resp.retmsg });
         }
 
+        // Heuristic login-expiry detection: an expired session returns
+        // neither a msgs field nor a fresh cursor. A healthy poll always
+        // carries one (idle -> msgs:[] + buf; active -> msgs:[...]).
+        const looksExpired = resp.msgs === undefined && !resp.get_updates_buf;
+        if (looksExpired) {
+          expiredShapeStreak++;
+          if (expiredShapeStreak >= EXPIRED_SHAPE_THRESHOLD && !expiryAlerted) {
+            expiryAlerted = true;
+            logger.warn('Login state appears to have silently expired', { consecutive: expiredShapeStreak });
+            try {
+              callbacks.onSessionLikelyExpired?.();
+            } catch (err) {
+              logger.warn('onSessionLikelyExpired handler threw', { error: err instanceof Error ? err.message : String(err) });
+            }
+          }
+        } else {
+          expiredShapeStreak = 0;
+          expiryAlerted = false;
+        }
         // Save the new sync buffer regardless of ret
         if (resp.get_updates_buf) {
           saveSyncBuf(resp.get_updates_buf);