Serve Google calendar app config from Jarvis

lib/app_shell.dart

@@ -351,6 +351,7 @@ class _HomeShellState extends State<HomeShell> {
           connections: widget.googleConnections,
           cachedEvents: widget.syncedEvents,
           people: widget.people,
+          jarvisSettings: widget.jarvisSettings,
           onChanged: widget.onGoogleConnectionsChanged,
           onSyncedEventsChanged: widget.onSyncedEventsChanged,
         ),

lib/google_calendar_page.dart

@@ -6,6 +6,7 @@ class AccountsPage extends StatefulWidget {
     required this.connections,
     required this.cachedEvents,
     required this.people,
+    required this.jarvisSettings,
     required this.onChanged,
     required this.onSyncedEventsChanged,
   });
@@ -13,6 +14,7 @@ class AccountsPage extends StatefulWidget {
   final List<GoogleCalendarConnection> connections;
   final List<CalendarEvent> cachedEvents;
   final List<Person> people;
+  final JarvisSettings jarvisSettings;
   final ValueChanged<List<GoogleCalendarConnection>> onChanged;
   final ValueChanged<List<CalendarEvent>> onSyncedEventsChanged;
 
@@ -28,6 +30,7 @@ class _AccountsPageState extends State<AccountsPage> {
   final googleSignIn = GoogleSignIn.instance;
   List<GoogleCalendarInfo> googleCalendars = [];
   GoogleSignInAccount? signedInAccount;
+  String runtimeServerClientId = googleCalendarServerClientId;
   bool initialized = false;
   bool loadingCalendars = false;
   bool syncing = false;
@@ -36,17 +39,62 @@ class _AccountsPageState extends State<AccountsPage> {
   @override
   void initState() {
     super.initState();
-    if (googleCalendarServerClientId.trim().isEmpty) {
-      statusMessage =
-          'A Google napt\u00e1rkapcsolat m\u00e9g nincs bek\u00f6tve ebbe az appverzi\u00f3ba. A csal\u00e1dtagoknak nem kell client ID-t megadniuk; ezt egyszer, fejleszt\u0151i be\u00e1ll\u00edt\u00e1sk\u00e9nt kell az apphoz rendelni.';
-    } else {
-      _initializeGoogle();
-    }
+    _loadGoogleAppConfigAndInitialize();
   }
 
   GoogleCalendarConnection? get connection =>
       widget.connections.isEmpty ? null : widget.connections.first;
 
+  Future<void> _loadGoogleAppConfigAndInitialize() async {
+    setState(() {
+      loadingCalendars = true;
+      statusMessage = 'Google napt\u00e1rkapcsolat el\u0151k\u00e9sz\u00edt\u00e9se...';
+    });
+
+    final configuredClientId = await _loadGoogleServerClientId();
+    if (!mounted) return;
+    if (configuredClientId == null || configuredClientId.trim().isEmpty) {
+      setState(() {
+        loadingCalendars = false;
+        statusMessage =
+            'A Google napt\u00e1rkapcsolat m\u00e9g nincs bek\u00f6tve. A csal\u00e1dtagoknak nem kell client ID-t megadniuk; a JARVIS admin fel\u00fcleten kell egyszer be\u00e1ll\u00edtani a Google Calendar OAuth azonos\u00edt\u00f3t.';
+      });
+      return;
+    }
+
+    runtimeServerClientId = configuredClientId.trim();
+    await _initializeGoogle();
+  }
+
+  Future<String?> _loadGoogleServerClientId() async {
+    if (googleCalendarServerClientId.trim().isNotEmpty) {
+      return googleCalendarServerClientId.trim();
+    }
+
+    final apiToken = widget.jarvisSettings.apiToken.trim();
+    if (apiToken.isEmpty) {
+      return null;
+    }
+
+    try {
+      final baseUri = Uri.parse(normalizeJarvisUrl(widget.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 null;
+      }
+      final payload = jsonDecode(response.body);
+      if (payload is! Map<String, dynamic>) {
+        return null;
+      }
+      return payload['googleCalendarServerClientId'] as String?;
+    } catch (_) {
+      return null;
+    }
+  }
+
   Future<void> _initializeGoogle() async {
     setState(() {
       loadingCalendars = true;
@@ -121,10 +169,10 @@ class _AccountsPageState extends State<AccountsPage> {
   }
 
   Future<void> _ensureGoogleInitialized() async {
-    final clientId = googleCalendarServerClientId.trim();
+    final clientId = runtimeServerClientId.trim();
     if (clientId.isEmpty) {
       throw Exception(
-        'A Google napt\u00e1rkapcsolat m\u00e9g nincs bek\u00f6tve ebbe az appverzi\u00f3ba.',
+        'A Google napt\u00e1rkapcsolat m\u00e9g nincs bek\u00f6tve.',
       );
     }