refactor: rename ObjectMetadataItem to EnrichedObjectMetadataItem and clean up metadata flows (#18830)

## Summary

- Renames `ObjectMetadataItem` to `EnrichedObjectMetadataItem` across
the entire frontend (~440 files) to clarify that this type includes
derived fields (`readableFields`, `updatableFields`, nested `fields[]`,
`indexMetadatas[]`) computed at read time from the metadata store
- Creates `splitObjectMetadataGqlResponse` that goes directly from a
GraphQL `ObjectMetadataItemsQuery` response to flat store items
(combining the old
`mapPaginatedObjectMetadataItemsToObjectMetadataItems` +
`splitObjectMetadataItemWithRelated` two-step flow into one call)
- Removes `ObjectMetadataItemWithRelated` type and all "WithRelated"
naming
- Renames `generatedMockObjectMetadataItems` to
`generateTestEnrichedObjectMetadataItemsMock` to make it clear this is
test-only enriched data
- Deletes `useLoadMockedObjectMetadataItems` hook (consolidated into
`useLoadMockedMinimalMetadata`)
- Ensures nothing destined for the metadata store computes
`readableFields`/`updatableFields` (preventing the localStorage bloat
from #18809)

## Type hierarchy (before → after)

**Before:**
```
ObjectMetadataItemsQuery → mapPaginated → ObjectMetadataItemWithRelated → enrich → ObjectMetadataItem
                                        → split → FlatObjectMetadataItem (store)
```

**After:**
```
ObjectMetadataItemsQuery → splitObjectMetadataGqlResponse → FlatObjectMetadataItem (store)
                         → mapPaginated + enrich (tests only) → EnrichedObjectMetadataItem
```

## Test plan

- [x] `npx nx typecheck twenty-front` passes
- [x] `npx nx test twenty-front` passes (767 suites, 4505 tests)
- [x] `npx nx lint twenty-front` passes
- [ ] CI checks pass


Made with [Cursor](https://cursor.com)

packages/twenty-front/src/modules/object-metadata/utils/enrichObjectMetadataItemsWithPermissions.ts

@@ -3,11 +3,11 @@ import { getNonUpdatableFieldMetadataIdsFromObjectPermissions } from '@/object-m
 import { getObjectPermissionsFromMapByObjectMetadataId } from '@/settings/roles/role-permissions/objects-permissions/utils/getObjectPermissionsFromMapByObjectMetadataId';
 import { type ObjectPermissions } from 'twenty-shared/types';
 import { isDefined } from 'twenty-shared/utils';
-import { type ObjectMetadataItem } from '@/object-metadata/types/ObjectMetadataItem';
+import { type EnrichedObjectMetadataItem } from '@/object-metadata/types/EnrichedObjectMetadataItem';
 
 type enrichObjectMetadataItemsWithPermissionsArgs = {
   objectMetadataItems: Omit<
-    ObjectMetadataItem,
+    EnrichedObjectMetadataItem,
     'readableFields' | 'updatableFields'
   >[];
   objectPermissionsByObjectMetadataId: Record<
@@ -20,7 +20,7 @@ export const enrichObjectMetadataItemsWithPermissions = ({
   objectMetadataItems,
   objectPermissionsByObjectMetadataId,
 }: enrichObjectMetadataItemsWithPermissionsArgs) => {
-  const formattedObjects: ObjectMetadataItem[] =
+  const formattedObjects: EnrichedObjectMetadataItem[] =
     objectMetadataItems.map((object) => {
       const objectPermissions = getObjectPermissionsFromMapByObjectMetadataId({
         objectPermissionsByObjectMetadataId,
@@ -50,7 +50,7 @@ export const enrichObjectMetadataItemsWithPermissions = ({
         updatableFields: fields.filter(
           (field) => !nonUpdatableFieldMetadataIds.includes(field.id),
         ),
-      } satisfies ObjectMetadataItem;
+      } satisfies EnrichedObjectMetadataItem;
     }) ?? [];
 
   return formattedObjects;