refactor: metadata store cleanup, SSE unification, mock metadata loading & login redirect fix (#18651)

## Summary
- **SSE unification**: Replaced 11 individual SSE effect components with
a single generic `MetadataStoreSSEEffect`
- **Metadata store cleanup**: Merged `metadataCollectionHashesState`
into `metadataStoreState` (currentCollectionHash / draftCollectionHash
per entity), moved `objectMetadataItemsSelector` to `object-metadata`
domain, converted `navigationMenuItemsState` to a derived selector
- **Naming clarity**: Renamed `isAppMetadataReadyState` →
`isMinimalMetadataReadyState`, `MetadataGater` → `MinimalMetadataGater`,
`useIsLogged` → `useHasAccessTokenPair`,
`patchMetadataStoreFromSSEEvent` now takes named object params
- **Mock metadata loading**: Added `generate-navigation-menu-items.ts`
script, rewrote `useLoadMockedMinimalMetadata` to load full
objects/fields/indexes/views/navItems from generated mock data, enabling
proper sign-in background rendering (table columns, view picker,
navigation)
- **Login/logout transitions**: `MinimalMetadataLoadEffect` manages
mocked↔real metadata transitions based on auth state,
`MainContextStoreProvider` computes context on auth pages for view
picker support
- **Login redirect fix**: `handleLoadWorkspaceAfterAuthentication` now
re-enables `isAppEffectRedirectEnabled` after `loadCurrentUser()`
completes, fixing the blocked post-login navigation
- **Dead code removal**: Deleted `useRefreshPageLayouts`,
`useApplyPageLayouts`, `useStaleMetadataEntities`,
`metadataCollectionHashesState`, and all individual SSE effects

## Test plan
- [x] Login from welcome page redirects to companies page
- [x] Logout transitions cleanly to mocked metadata on welcome page
- [x] Sign-in background shows table columns, view picker, and
navigation items
- [x] SSE events still update metadata store entries correctly
- [x] Navigation menu items persist across page refreshes
- [ ] CI: lint, typecheck, tests pass

packages/twenty-front/src/modules/object-metadata/hooks/useCreateOneObjectMetadataItem.ts

@@ -5,21 +5,12 @@ import {
 } from '~/generated-metadata/graphql';
 
 import { useMetadataErrorHandler } from '@/metadata-error-handler/hooks/useMetadataErrorHandler';
-import { useRefreshObjectMetadataItems } from '@/object-metadata/hooks/useRefreshObjectMetadataItems';
 import { type MetadataRequestResult } from '@/object-metadata/types/MetadataRequestResult.type';
 import { useSnackBar } from '@/ui/feedback/snack-bar-manager/hooks/useSnackBar';
-import { useRefreshCoreViewsByObjectMetadataId } from '@/views/hooks/useRefreshCoreViewsByObjectMetadataId';
 import { CombinedGraphQLErrors } from '@apollo/client/errors';
 import { t } from '@lingui/core/macro';
 import { CrudOperationType } from 'twenty-shared/types';
-import { isDefined } from 'twenty-shared/utils';
-
 export const useCreateOneObjectMetadataItem = () => {
-  const { refreshObjectMetadataItems } =
-    useRefreshObjectMetadataItems('network-only');
-  const { refreshCoreViewsByObjectMetadataId } =
-    useRefreshCoreViewsByObjectMetadataId();
-
   const [createOneObjectMetadataItemMutation] = useMutation(
     CreateOneObjectMetadataItemDocument,
   );
@@ -41,14 +32,6 @@ export const useCreateOneObjectMetadataItem = () => {
         },
       });
 
-      await refreshObjectMetadataItems();
-
-      if (isDefined(createdObjectMetadata.data?.createOneObject?.id)) {
-        await refreshCoreViewsByObjectMetadataId(
-          createdObjectMetadata.data.createOneObject.id,
-        );
-      }
-
       return {
         status: 'successful',
         response: createdObjectMetadata,