diff --git a/apps/mobile-shell/scripts/check-config.mjs b/apps/mobile-shell/scripts/check-config.mjs
index a1bf7bc51..78afe9af2 100644
--- a/apps/mobile-shell/scripts/check-config.mjs
+++ b/apps/mobile-shell/scripts/check-config.mjs
@@ -2402,6 +2402,7 @@ for (const snippet of [
   "message: 'qr scanner unavailable'",
   "message: 'qr scan cancelled'",
   "test('logs and rejects the active scan when camera permission request fails'",
+  "test('ignores late camera permission after the scan is cancelled'",
   "'mobile QR scanner permission request failed'",
   "barcodeTypes: ['qr']",
   "type: 'qr'",
diff --git a/apps/mobile-shell/src/shell/QrScannerOverlay.test.tsx b/apps/mobile-shell/src/shell/QrScannerOverlay.test.tsx
index 274c99437..f5ca3fcd1 100644
--- a/apps/mobile-shell/src/shell/QrScannerOverlay.test.tsx
+++ b/apps/mobile-shell/src/shell/QrScannerOverlay.test.tsx
@@ -1,6 +1,6 @@
 /* @vitest-environment jsdom */
 
-import { render, waitFor } from '@testing-library/react';
+import { act, render, waitFor } from '@testing-library/react';
 import * as CameraModule from 'expo-camera';
 import React from 'react';
 import { afterEach, describe, expect, test, vi } from 'vitest';
@@ -62,6 +62,23 @@ const cameraPermissionMock = vi.mocked(
   CameraModule.Camera.requestCameraPermissionsAsync,
 );
 
+function createDeferredPermission() {
+  let resolvePermission!: (
+    permission: Awaited<
+      ReturnType<typeof CameraModule.Camera.requestCameraPermissionsAsync>
+    >,
+  ) => void;
+  const promise = new Promise<
+    Awaited<ReturnType<typeof CameraModule.Camera.requestCameraPermissionsAsync>>
+  >((resolve) => {
+    resolvePermission = resolve;
+  });
+  return {
+    promise,
+    resolvePermission,
+  };
+}
+
 describe('QrScannerOverlay', () => {
   afterEach(() => {
     resetQrScannerForTest();
@@ -156,4 +173,32 @@ describe('QrScannerOverlay', () => {
       message: 'qr scan cancelled',
     });
   });
+
+  test('ignores late camera permission after the scan is cancelled', async () => {
+    const permission = createDeferredPermission();
+    cameraPermissionMock.mockReturnValue(permission.promise);
+    const screen = render(<QrScannerOverlay />);
+
+    const scanPromise = scanQrCode();
+
+    await waitFor(() => {
+      expect(screen.getByText('关闭')).toBeTruthy();
+    });
+
+    screen.getByText('关闭').click();
+
+    await expect(scanPromise).rejects.toMatchObject({
+      code: 'cancelled',
+      message: 'qr scan cancelled',
+    });
+
+    await act(async () => {
+      permission.resolvePermission({
+        granted: true,
+      } as Awaited<ReturnType<typeof CameraModule.Camera.requestCameraPermissionsAsync>>);
+      await permission.promise;
+    });
+
+    expect(overlayHarness.cameraViewProps.current).toBeNull();
+  });
 });
diff --git a/docs/project-memory/shared-memory/decision-log.md b/docs/project-memory/shared-memory/decision-log.md
index 9e97b0904..c0dd38901 100644
--- a/docs/project-memory/shared-memory/decision-log.md
+++ b/docs/project-memory/shared-memory/decision-log.md
@@ -16,6 +16,14 @@
 
 ---
 
+## 2026-06-20 移动扫码权限异步取消边界
+
+- 背景：Expo 移动壳 `scanner.scanQrCode` 会打开真实相机权限请求和扫码 overlay；如果用户在系统权限 Promise 返回前关闭扫码，旧权限结果不能重新激活 CameraView，也不能完成已经取消的 HostBridge 请求。
+- 决策：`QrScannerOverlay` 必须在 active/requestKey 变化和组件清理时忽略迟到的权限结果；移动壳配置检查必须反查“取消后迟到权限不重新打开 CameraView”的测试用例。
+- 影响范围：`apps/mobile-shell/src/shell/QrScannerOverlay.tsx`、`apps/mobile-shell/src/shell/QrScannerOverlay.test.tsx`、`apps/mobile-shell/scripts/check-config.mjs`。
+- 验证方式：`npm run mobile-shell:test -- src/shell/QrScannerOverlay.test.tsx`、`npm run mobile-shell:typecheck`、`npm run check:native-shells`、`npm run check:encoding`、`git diff --check`。
+- 关联文档：`docs/【前端架构】ExpoReactNative与Tauri宿主壳方案-2026-06-17.md`、`docs/【前端架构】宿主壳能力统一协议-2026-06-17.md`。
+
 ## 2026-06-20 桌面壳系统能力调用顺序门禁
 
 - 背景：Tauri 桌面壳文件导出和本地通知已经在运行时代码中先校验 HostBridge payload，再打开系统保存对话框、读取通知权限或请求通知权限；如果后续重构把系统能力调用提前，非法请求会触达原生系统边界。