接入移动端原生扫码能力

新增 scanner.scanQrCode HostBridge 契约与二维码结果归一。

接入 Expo Camera 扫码 overlay 并保留 H5 浏览器扫码回退。

让 Tauri 白名单识别扫码 method 但不声明桌面扫码能力。

同步原生壳门禁、Expo 权限检查、方案文档和共享决策记录。

src/components/rpg-entry/RpgEntryHomeView.tsx

@@ -73,6 +73,7 @@ import {
   canUseNativeHostCapability,
   type HostFileImportImageResult,
   importHostImageFile,
+  scanHostQrCode,
 } from '../../services/host-bridge/hostBridge';
 import { shouldShowRechargeEntry } from '../../services/payment/paymentPlatform';
 import type { CustomWorldProfile } from '../../types';
@@ -2595,6 +2596,9 @@ export function RpgEntryHomeView({
   const [activeWorkSearchKeyword, setActiveWorkSearchKeyword] = useState('');
   const [isQrScannerOpen, setIsQrScannerOpen] = useState(false);
   const [qrScannerError, setQrScannerError] = useState<string | null>(null);
+  const [qrScannerMode, setQrScannerMode] = useState<'camera' | 'resultOnly'>(
+    'camera',
+  );
   const [qrScannerResult, setQrScannerResult] = useState<string | null>(null);
   const [selectedCategoryTag, setSelectedCategoryTag] = useState<string | null>(
     null,
@@ -3160,7 +3164,32 @@ export function RpgEntryHomeView({
 
     setQrScannerError(null);
     setQrScannerResult(null);
-    setIsQrScannerOpen(true);
+    setQrScannerMode('camera');
+
+    void scanHostQrCode()
+      .then((result) => {
+        if (result === null) {
+          return;
+        }
+
+        if (result) {
+          setQrScannerMode('resultOnly');
+          setQrScannerResult(result.value);
+          setIsQrScannerOpen(true);
+          return;
+        }
+
+        setQrScannerMode('camera');
+        setIsQrScannerOpen(true);
+      })
+      .catch((error: unknown) => {
+        setQrScannerMode('resultOnly');
+        setQrScannerResult(null);
+        setQrScannerError(
+          error instanceof Error ? error.message : '扫码失败，请稍后重试',
+        );
+        setIsQrScannerOpen(true);
+      });
   };
   const clearWorkSearch = () => {
     setActiveWorkSearchKeyword('');
@@ -4873,9 +4902,11 @@ export function RpgEntryHomeView({
   const qrScannerModal: ReactNode = isQrScannerOpen ? (
     <PlatformProfileQrScannerModal
       error={qrScannerError}
+      mode={qrScannerMode}
       result={qrScannerResult}
       onClose={() => {
         setIsQrScannerOpen(false);
+        setQrScannerMode('camera');
         setQrScannerError(null);
         setQrScannerResult(null);
       }}