Generate GQL schema based on applicationId (#17860)

## Add application-scoped GraphQL schema generation

When an application token is used to authenticate, the `/graphql` schema
is now dynamically filtered to only include entities belonging to that
application (plus the Twenty Standard Application). This enables
third-party applications and the SDK to introspect a schema that is
relevant to their scope, rather than seeing the full workspace schema
with all custom objects.

### Changes

- **New `generateApplicationToken` mutation** on the `/metadata`
endpoint, allowing callers to exchange an API key for an
application-scoped JWT token
- **Schema filtering by application** in `WorkspaceSchemaFactory` — when
`request.application` is present (from an application token), flat
entity maps are filtered by `[appId, standardAppId]` before schema
generation
- **Per-app caching** — both the Yoga in-memory cache and Redis cache
now include the `appId` in their keys to avoid serving wrong schemas
- **Consolidated `getSubFlatEntityMapsByApplicationIdsOrThrow`** —
unified the single-ID and multi-ID filtering utilities into one
- **Integration tests** covering token generation (admin + API key auth)
and schema introspection filtering (standard app token excludes custom
objects)

Schema generated on seeds with applicationToken (see that pets is
missing)
<img width="782" height="994" alt="image"
src="https://github.com/user-attachments/assets/82510031-0965-435d-bc26-77c9f5d74e1f"
/>

packages/twenty-server/src/engine/metadata-modules/flat-entity/utils/get-sub-flat-entity-maps-by-application-ids-or-throw.util.ts

@@ -3,22 +3,28 @@ import { type FlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/typ
 import { findFlatEntitiesByApplicationId } from 'src/engine/metadata-modules/flat-entity/utils/find-flat-entities-by-application-id.util';
 import { getSubFlatEntityByIdsMapsOrThrow } from 'src/engine/metadata-modules/flat-entity/utils/get-sub-flat-entity-by-ids-maps-or-throw.util';
 
-export const getSubFlatEntityMapsByApplicationIdOrThrow = <
+export const getSubFlatEntityMapsByApplicationIdsOrThrow = <
   T extends SyncableFlatEntity,
 >({
-  applicationId,
+  applicationIds,
   flatEntityMaps,
 }: {
-  applicationId: string;
+  applicationIds: string[];
   flatEntityMaps: FlatEntityMaps<T>;
 }) => {
-  const allApplicationFlatEntity = findFlatEntitiesByApplicationId({
-    applicationId,
-    flatEntityMaps,
+  const allFlatEntityIds = applicationIds.flatMap((applicationId) => {
+    const entities = findFlatEntitiesByApplicationId({
+      applicationId,
+      flatEntityMaps,
+    });
+
+    return entities.map((entity) => entity.id);
   });
 
+  const uniqueFlatEntityIds = [...new Set(allFlatEntityIds)];
+
   return getSubFlatEntityByIdsMapsOrThrow({
-    flatEntityIds: allApplicationFlatEntity.map((flatEntity) => flatEntity.id),
+    flatEntityIds: uniqueFlatEntityIds,
     flatEntityMaps,
   });
 };