fix: 退出启动对话框时终端残留一行内容

gracefulShutdownSync 启动异步 shutdown 后同步返回，React 立即
重新渲染组件，与 cleanupTerminalModes() 中的 Ink unmount 产生
竞态条件，导致退出后终端残留对话框内容。

修复方案：引入 pendingExitCode state，退出路径先清空画面
（渲染 null），在 useEffect 中延迟到下一个 tick 再调用
gracefulShutdownSync，确保 Ink 在终端清理前已完成空帧刷新。

影响三个启动对话框：TrustDialog、BypassPermissionsModeDialog、
DevChannelsDialog。

Co-Authored-By: glm-5.1 <zai-org@claude-code-best.win>

src/components/BypassPermissionsModeDialog.tsx

@@ -11,6 +11,18 @@ type Props = {
 };
 
 export function BypassPermissionsModeDialog({ onAccept }: Props): React.ReactNode {
+  const [pendingExitCode, setPendingExitCode] = React.useState<number | null>(null);
+
+  // Clear screen before shutdown so residual dialog content doesn't leak
+  // to the terminal. Deferred to next tick so Ink flushes the null render.
+  React.useEffect(() => {
+    if (pendingExitCode !== null) {
+      const code = pendingExitCode;
+      const timer = setTimeout(() => gracefulShutdownSync(code));
+      return () => clearTimeout(timer);
+    }
+  }, [pendingExitCode]);
+
   React.useEffect(() => {
     logEvent('tengu_bypass_permissions_mode_dialog_shown', {});
   }, []);
@@ -27,16 +39,20 @@ export function BypassPermissionsModeDialog({ onAccept }: Props): React.ReactNod
         break;
       }
       case 'decline': {
-        gracefulShutdownSync(1);
+        setPendingExitCode(1);
         break;
       }
     }
   }
 
   const handleEscape = useCallback(() => {
-    gracefulShutdownSync(0);
+    setPendingExitCode(0);
   }, []);
 
+  if (pendingExitCode !== null) {
+    return null;
+  }
+
   return (
     <Dialog title="WARNING: Claude Code running in Bypass Permissions mode" color="error" onCancel={handleEscape}>
       <Box flexDirection="column" gap={1}>

src/components/DevChannelsDialog.tsx

@@ -10,21 +10,37 @@ type Props = {
 };
 
 export function DevChannelsDialog({ channels, onAccept }: Props): React.ReactNode {
+  const [pendingExitCode, setPendingExitCode] = React.useState<number | null>(null);
+
+  // Clear screen before shutdown so residual dialog content doesn't leak
+  // to the terminal. Deferred to next tick so Ink flushes the null render.
+  React.useEffect(() => {
+    if (pendingExitCode !== null) {
+      const code = pendingExitCode;
+      const timer = setTimeout(() => gracefulShutdownSync(code));
+      return () => clearTimeout(timer);
+    }
+  }, [pendingExitCode]);
+
   function onChange(value: 'accept' | 'exit') {
     switch (value) {
       case 'accept':
         onAccept();
         break;
       case 'exit':
-        gracefulShutdownSync(1);
+        setPendingExitCode(1);
         break;
     }
   }
 
   const handleEscape = useCallback(() => {
-    gracefulShutdownSync(0);
+    setPendingExitCode(0);
   }, []);
 
+  if (pendingExitCode !== null) {
+    return null;
+  }
+
   return (
     <Dialog title="WARNING: Loading development channels" color="error" onCancel={handleEscape}>
       <Box flexDirection="column" gap={1}>

src/components/TrustDialog/TrustDialog.tsx

@@ -80,6 +80,21 @@ export function TrustDialog({ onDone, commands }: Props): React.ReactNode {
   const hasAnyBashExecution = bashSettingSources.length > 0 || hasSlashCommandBash || hasSkillsBash;
 
   const hasTrustDialogAccepted = checkHasTrustDialogAccepted();
+  const [pendingExitCode, setPendingExitCode] = React.useState<number | null>(null);
+
+  // When a non-null exit code is set, render null (clear screen) first,
+  // then trigger shutdown in the next tick so Ink has time to flush
+  // the empty frame before cleanupTerminalModes() unmounts and exits
+  // the alt screen. Without this deferral, gracefulShutdownSync starts
+  // async cleanup immediately after React commit, racing the reconciler
+  // and leaving residual TrustDialog output on the terminal.
+  React.useEffect(() => {
+    if (pendingExitCode !== null) {
+      const code = pendingExitCode;
+      const timer = setTimeout(() => gracefulShutdownSync(code));
+      return () => clearTimeout(timer);
+    }
+  }, [pendingExitCode]);
 
   React.useEffect(() => {
     const isHomeDir = homedir() === getCwd();
@@ -107,7 +122,12 @@ export function TrustDialog({ onDone, commands }: Props): React.ReactNode {
 
   function onChange(value: 'enable_all' | 'exit') {
     if (value === 'exit') {
-      gracefulShutdownSync(1);
+      // Set pendingExitCode to clear the screen before triggering shutdown.
+      // The useEffect above defers gracefulShutdownSync to the next tick
+      // so Ink can flush the empty frame first — otherwise
+      // cleanupTerminalModes races React's re-render and leaves
+      // residual TrustDialog content on the terminal.
+      setPendingExitCode(1);
       return;
     }
 
@@ -151,17 +171,23 @@ export function TrustDialog({ onDone, commands }: Props): React.ReactNode {
   // so the default would hang the await forever. With keybinding
   // customization enabled, the chokidar watcher (persistent: true) keeps the
   // event loop alive and the process freezes. Explicitly exit 1 like "No".
-  const exitState = useExitOnCtrlCDWithKeybindings(() => gracefulShutdownSync(1));
+  const exitState = useExitOnCtrlCDWithKeybindings(() => setPendingExitCode(1));
 
   // Use configurable keybinding for ESC to cancel/exit
   useKeybinding(
     'confirm:no',
     () => {
-      gracefulShutdownSync(0);
+      setPendingExitCode(0);
     },
     { context: 'Confirmation' },
   );
 
+  // When pendingExitCode is set, render nothing so the screen is cleared
+  // before shutdown cleans up the alt screen.  See the useEffect above.
+  if (pendingExitCode !== null) {
+    return null;
+  }
+
   // Automatically resolve the trust dialog if there is nothing to be shown.
   if (hasTrustDialogAccepted) {
     setTimeout(onDone);