fix: improve transfer recognition and local data safety

frontend/lib/features/auth/pages/register_page.dart

@@ -2,6 +2,11 @@ import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:miaoji_zhang/shared/api/api_client.dart';
 import 'package:miaoji_zhang/shared/api/auth_api.dart';
+import 'package:miaoji_zhang/features/auth/local_data_recovery.dart';
+import 'package:miaoji_zhang/shared/services/current_ledger_store.dart';
+import 'package:miaoji_zhang/shared/services/local_database.dart';
+import 'package:miaoji_zhang/shared/services/push_service.dart';
+import 'package:miaoji_zhang/shared/services/session_store.dart';
 import 'package:miaoji_zhang/shared/theme/app_theme.dart';
 
 class RegisterPage extends StatefulWidget {
@@ -40,9 +45,26 @@ class _RegisterPageState extends State<RegisterPage> {
     }
     setState(() => _loading = true);
     try {
-      await AuthApi.register(username, _pass.text, agreedToTerms: _agreed);
+      final guestSnapshot = SessionStore.instance.isGuest
+          ? LocalDatabase.instance.guestSnapshot()
+          : null;
+      final profile = await AuthApi.register(
+        username,
+        _pass.text,
+        agreedToTerms: _agreed,
+      );
+      await PushService.instance.refresh();
+      await CurrentLedgerStore.instance.ensureLoaded(force: true);
       if (!mounted) return;
-      context.go('/onboarding');
+      await offerLocalDataRecovery(context, guestSnapshot: guestSnapshot);
+      if (!mounted) return;
+      context.go(
+        !profile.onboardingDone
+            ? '/onboarding'
+            : profile.appMode == 'ai'
+            ? '/ai-mode'
+            : '/home',
+      );
     } catch (error) {
       if (!mounted) return;
       _message(apiErrorMessage(error));