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-server/src/engine/metadata-modules/minimal-metadata/dtos/collection-hash.dto.ts

@@ -0,0 +1,15 @@
+import { Field, ObjectType } from '@nestjs/graphql';
+
+import {
+  ALL_METADATA_NAME,
+  type AllMetadataName,
+} from 'twenty-shared/metadata';
+
+@ObjectType('CollectionHash')
+export class CollectionHashDTO {
+  @Field(() => ALL_METADATA_NAME)
+  collectionName: AllMetadataName;
+
+  @Field(() => String)
+  hash: string;
+}

packages/twenty-server/src/engine/metadata-modules/minimal-metadata/dtos/minimal-metadata.dto.ts

@@ -1,6 +1,6 @@
 import { Field, ObjectType } from '@nestjs/graphql';
-import { GraphQLJSON } from 'graphql-type-json';
 
+import { CollectionHashDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/collection-hash.dto';
 import { MinimalObjectMetadataDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/minimal-object-metadata.dto';
 import { MinimalViewDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/minimal-view.dto';
 
@@ -12,6 +12,6 @@ export class MinimalMetadataDTO {
   @Field(() => [MinimalViewDTO])
   views: MinimalViewDTO[];
 
-  @Field(() => GraphQLJSON)
-  collectionHashes: Record<string, string>;
+  @Field(() => [CollectionHashDTO])
+  collectionHashes: CollectionHashDTO[];
 }

packages/twenty-server/src/engine/metadata-modules/minimal-metadata/minimal-metadata.service.ts

@@ -9,13 +9,13 @@ import { isDefined, uncapitalize } from 'twenty-shared/utils';
 
 import { ALL_FLAT_ENTITY_MAPS_PROPERTIES } from 'src/engine/metadata-modules/flat-entity/constant/all-flat-entity-maps-properties.constant';
 import { WorkspaceManyOrAllFlatEntityMapsCacheService } from 'src/engine/metadata-modules/flat-entity/services/workspace-many-or-all-flat-entity-maps-cache.service';
+import { type CollectionHashDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/collection-hash.dto';
 import { MinimalMetadataDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/minimal-metadata.dto';
 import { MinimalObjectMetadataDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/minimal-object-metadata.dto';
 import { MinimalViewDTO } from 'src/engine/metadata-modules/minimal-metadata/dtos/minimal-view.dto';
 import { WorkspaceCacheService } from 'src/engine/workspace-cache/services/workspace-cache.service';
 import { type WorkspaceCacheKeyName } from 'src/engine/workspace-cache/types/workspace-cache-key.type';
 
-// Inverse of getMetadataFlatEntityMapsKey: "flatObjectMetadataMaps" -> "objectMetadata"
 const flatMapsKeyToMetadataName = (
   flatMapsKey: string,
 ): AllMetadataName | undefined => {
@@ -51,15 +51,17 @@ export class MinimalMetadataService {
         ),
       ]);
 
-    const collectionHashes: Record<string, string> = {};
+    const collectionHashes: CollectionHashDTO[] = Object.entries(cacheHashes)
+      .map(([cacheKey, hash]) => {
+        const metadataName = flatMapsKeyToMetadataName(cacheKey);
 
-    for (const [cacheKey, hash] of Object.entries(cacheHashes)) {
-      const metadataName = flatMapsKeyToMetadataName(cacheKey);
+        if (!isDefined(metadataName) || !isDefined(hash)) {
+          return undefined;
+        }
 
-      if (isDefined(metadataName) && isDefined(hash)) {
-        collectionHashes[metadataName] = hash;
-      }
-    }
+        return { collectionName: metadataName, hash };
+      })
+      .filter(isDefined);
 
     const objectMetadataItems: MinimalObjectMetadataDTO[] = Object.values(
       flatObjectMetadataMaps.byUniversalIdentifier,

packages/twenty-server/src/engine/metadata-modules/view-field-group/services/fields-widget-upsert.service.ts

@@ -294,16 +294,17 @@ export class FieldsWidgetUpsertService {
         return [];
       }
 
-      const { viewFieldGroupUniversalIdentifier } =
-        resolveEntityRelationUniversalIdentifiers({
-          metadataName: 'viewField',
-          foreignKeyValues: {
-            viewFieldGroupId: newViewFieldGroupId,
-          },
-          flatEntityMaps: {
-            flatViewFieldGroupMaps: optimisticFlatViewFieldGroupMaps,
-          },
-        });
+      const {
+        viewFieldGroupUniversalIdentifier: _viewFieldGroupUniversalIdentifier,
+      } = resolveEntityRelationUniversalIdentifiers({
+        metadataName: 'viewField',
+        foreignKeyValues: {
+          viewFieldGroupId: newViewFieldGroupId,
+        },
+        flatEntityMaps: {
+          flatViewFieldGroupMaps: optimisticFlatViewFieldGroupMaps,
+        },
+      });
 
       const shouldOverride = isCallerOverridingEntity({
         callerApplicationUniversalIdentifier: applicationUniversalIdentifier,