Cache Jarvis app config on startup

lib/app_shell.dart

@@ -15,6 +15,7 @@ class _OtthonAppState extends State<OtthonApp> {
   List<CalendarEvent> syncedEvents = [];
   List<String> todoSuggestions = [];
   JarvisSettings jarvisSettings = JarvisSettings.defaults();
+  String googleServerClientId = googleCalendarServerClientId;
   WeatherSnapshot? weather;
   String themeId = 'sage';
   bool loaded = false;
@@ -40,9 +41,11 @@ class _OtthonAppState extends State<OtthonApp> {
       syncedEvents = settings.syncedEvents;
       todoSuggestions = settings.todoSuggestions;
       jarvisSettings = settings.jarvisSettings;
+      googleServerClientId = settings.googleServerClientId;
       themeId = settings.themeId;
       loaded = true;
     });
+    _loadRemoteAppConfig();
   }
 
   Future<void> _saveSettings() async {
@@ -54,10 +57,39 @@ class _OtthonAppState extends State<OtthonApp> {
         syncedEvents: syncedEvents,
         todoSuggestions: todoSuggestions,
         jarvisSettings: jarvisSettings,
+        googleServerClientId: googleServerClientId,
       ),
     );
   }
 
+  Future<void> _loadRemoteAppConfig() async {
+    final apiToken = jarvisSettings.apiToken.trim();
+    if (apiToken.isEmpty) return;
+
+    try {
+      final baseUri = Uri.parse(normalizeJarvisUrl(jarvisSettings.apiUrl));
+      final uri = baseUri.replace(path: '/api/app-config', query: '');
+      final response = await http
+          .get(uri, headers: {'X-Otthon-Token': apiToken})
+          .timeout(const Duration(seconds: 10));
+      if (response.statusCode != 200) return;
+      final payload = jsonDecode(response.body);
+      if (payload is! Map<String, dynamic>) return;
+      final remoteGoogleClientId =
+          payload['googleCalendarServerClientId'] as String?;
+      if (remoteGoogleClientId == null ||
+          remoteGoogleClientId.trim().isEmpty ||
+          remoteGoogleClientId == googleServerClientId) {
+        return;
+      }
+      if (!mounted) return;
+      setState(() => googleServerClientId = remoteGoogleClientId.trim());
+      _saveSettings();
+    } catch (_) {
+      // Offline mode keeps the locally cached app configuration.
+    }
+  }
+
   void _updatePeople(List<Person> nextPeople) {
     setState(() => people = nextPeople);
     _saveSettings();
@@ -88,6 +120,7 @@ class _OtthonAppState extends State<OtthonApp> {
   void _updateJarvisSettings(JarvisSettings nextSettings) {
     setState(() => jarvisSettings = nextSettings);
     _saveSettings();
+    _loadRemoteAppConfig();
   }
 
   Future<void> _loadWeather() async {
@@ -132,6 +165,7 @@ class _OtthonAppState extends State<OtthonApp> {
         syncedEvents: syncedEvents,
         todoSuggestions: todoSuggestions,
         jarvisSettings: jarvisSettings,
+        googleServerClientId: googleServerClientId,
         weather: weather,
         themeId: themeId,
         loaded: loaded,
@@ -154,6 +188,7 @@ class HomeShell extends StatefulWidget {
     required this.syncedEvents,
     required this.todoSuggestions,
     required this.jarvisSettings,
+    required this.googleServerClientId,
     required this.weather,
     required this.themeId,
     required this.loaded,
@@ -170,6 +205,7 @@ class HomeShell extends StatefulWidget {
   final List<CalendarEvent> syncedEvents;
   final List<String> todoSuggestions;
   final JarvisSettings jarvisSettings;
+  final String googleServerClientId;
   final WeatherSnapshot? weather;
   final String themeId;
   final bool loaded;
@@ -352,6 +388,7 @@ class _HomeShellState extends State<HomeShell> {
           cachedEvents: widget.syncedEvents,
           people: widget.people,
           jarvisSettings: widget.jarvisSettings,
+          serverClientId: widget.googleServerClientId,
           onChanged: widget.onGoogleConnectionsChanged,
           onSyncedEventsChanged: widget.onSyncedEventsChanged,
         ),