feat(messaging): webhook push sync for Gmail, Calendar and Microsoft (#21970)

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packages/twenty-server/src/engine/core-modules/feature-flag/constants/public-feature-flag.const.ts

@@ -28,6 +28,14 @@ export const PUBLIC_FEATURE_FLAGS: PublicFeatureFlag[] = [
         'Show the per-page hero illustration + video walkthrough modal on settings pages',
     },
   },
+  {
+    key: FeatureFlagKey.IS_MESSAGING_CALENDAR_WEBHOOK_ENABLED,
+    metadata: {
+      label: 'Messaging & Calendar Webhooks',
+      description:
+        'Sync Gmail, Google Calendar, and Microsoft 365 mail/calendar via provider push notifications instead of cron polling',
+    },
+  },
   ...(process.env.CLOUDFLARE_API_KEY
     ? [
         // {