feat(video_calls): ios voip push handling fix

lib/core/firebase_api.dart

@@ -69,13 +69,13 @@ class FirebaseApi {
   }
 
   Future<void> registerPushToken() async {
-    if (await TokenStorage.haveTokenInStorage()) {
-      try {
-        await _requestNotificationPermission();
-        final deviceInfo = DeviceInfoPlugin();
-        final credentials = await _resolvePushCredentials();
-        final token = credentials.token;
-        if (token == null || token.isEmpty) return;
+    if (!await TokenStorage.haveTokenInStorage()) return;
+    try {
+      await _requestNotificationPermission();
+      final deviceInfo = DeviceInfoPlugin();
+      final credentials = await _resolvePushCredentials();
+      final token = credentials.token;
+      if (token != null && token.isNotEmpty) {
         await sl<Dio>().post(
           '/api/profile/notification/token/register',
           data: {
@@ -89,14 +89,17 @@ class FirebaseApi {
             throw TimeoutException('registerPushToken timeout');
           },
         );
-        if (Platform.isIOS) {
-          await _registerIosVoipPushToken();
-        }
-      } catch (e, st) {
-        log(e.toString(), stackTrace: st);
-        await _errorReporter.report(e, st, origin: 'FirebaseApi');
-        // Не пробрасываем ошибку дальше, так как это не критичная операция
       }
+    } catch (e, st) {
+      log(e.toString(), stackTrace: st);
+      await _errorReporter.report(e, st, origin: 'FirebaseApi');
+      // Не пробрасываем ошибку дальше, так как это не критичная операция
+    }
+    // Incoming calls on iOS come only through the VoIP token. It does not
+    // depend on the FCM token, so a missing or failed FCM registration must
+    // not leave the device without calls.
+    if (Platform.isIOS) {
+      await _registerIosVoipPushToken();
     }
   }