feat(home): 重构首页为底部导航栏布局，支持首页与个人页面切换

apps/lib/app/app.dart

@@ -242,15 +242,31 @@ class _EryaoAppState extends State<EryaoApp> {
     return updated;
   }
 
+  Future<ProfileSettingsV1> _saveProfile(ProfileSettingsV1 updated) async {
+    final saved = await _profileApi.updateProfile(updated);
+    if (!mounted) {
+      return saved;
+    }
+    setState(() {
+      _profileSettings = saved;
+    });
+    return saved;
+  }
+
   Future<void> _saveProfileSettings(ProfileSettingsV1 next) async {
     try {
-      final saved = await _profileApi.updateProfile(next);
+      final oldLanguage = _profileSettings.preferences.interfaceLanguage;
+      final newLanguage = next.preferences.interfaceLanguage;
+      final saved = await _profileApi.updateSettings(next);
       if (!mounted) {
         return;
       }
       setState(() {
         _profileSettings = saved;
       });
+      if (oldLanguage != newLanguage) {
+        await _handleInterfaceLanguageChanged(newLanguage);
+      }
     } catch (error, stackTrace) {
       _logger.error(
         message: 'Failed to save profile settings via API',
@@ -341,6 +357,7 @@ class _EryaoAppState extends State<EryaoApp> {
         coinBalance: _creditsBalance,
         onLocaleChanged: _handleInterfaceLanguageChanged,
         onProfileSettingsChanged: _saveProfileSettings,
+        onSaveProfile: _saveProfile,
         onUploadAvatar: _uploadAvatar,
         onDivinationCompleted: _handleDivinationCompleted,
         onLogout: _authBloc.logout,