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-record/object-options-dropdown/hooks/useSetViewTypeFromLayoutOptionsMenu.ts

@@ -5,11 +5,10 @@ import { useRecordIndexContextOrThrow } from '@/object-record/record-index/conte
 import { useLoadRecordIndexStates } from '@/object-record/record-index/hooks/useLoadRecordIndexStates';
 import { recordIndexViewTypeState } from '@/object-record/record-index/states/recordIndexViewTypeState';
 import { useUpdateCurrentView } from '@/views/hooks/useUpdateCurrentView';
-import { coreViewsState } from '@/views/states/coreViewState';
+import { coreViewsSelector } from '@/views/states/selectors/coreViewsSelector';
 import { type GraphQLView } from '@/views/types/GraphQLView';
 import { ViewType, viewTypeIconMapping } from '@/views/types/ViewType';
 import { convertCoreViewToView } from '@/views/utils/convertCoreViewToView';
-import { convertViewTypeToCore } from '@/views/utils/convertViewTypeToCore';
 import { useGetAvailableFieldsForCalendar } from '@/views/view-picker/hooks/useGetAvailableFieldsForCalendar';
 import { useGetAvailableFieldsToGroupRecordsBy } from '@/views/view-picker/hooks/useGetAvailableFieldsToGroupRecordsBy';
 import { useSetAtomState } from '@/ui/utilities/state/jotai/hooks/useSetAtomState';
@@ -39,7 +38,7 @@ export const useSetViewTypeFromLayoutOptionsMenu = () => {
         }),
       );
 
-      const existingCoreViews = store.get(coreViewsState.atom);
+      const existingCoreViews = store.get(coreViewsSelector.atom);
 
       if (!isDefined(currentViewId)) {
         throw new Error('No view id found');
@@ -74,16 +73,6 @@ export const useSetViewTypeFromLayoutOptionsMenu = () => {
           }
 
           setRecordIndexViewType(viewType);
-          store.set(coreViewsState.atom, [
-            ...existingCoreViews.filter(
-              (coreView) => coreView.id !== currentView.id,
-            ),
-            {
-              ...currentCoreView,
-              type: convertViewTypeToCore(viewType),
-              mainGroupByFieldMetadataId,
-            },
-          ]);
           await updateCurrentView(updateCurrentViewParams);
           return;
         }
@@ -95,16 +84,6 @@ export const useSetViewTypeFromLayoutOptionsMenu = () => {
           updateCurrentViewParams.mainGroupByFieldMetadataId = null;
           await updateCurrentView(updateCurrentViewParams);
           setRecordIndexViewType(viewType);
-          store.set(coreViewsState.atom, [
-            ...existingCoreViews.filter(
-              (coreView) => coreView.id !== currentView.id,
-            ),
-            {
-              ...currentCoreView,
-              mainGroupByFieldMetadataId: null,
-              type: convertViewTypeToCore(viewType),
-            },
-          ]);
           return;
         }
         case ViewType.Calendar: {
@@ -115,18 +94,6 @@ export const useSetViewTypeFromLayoutOptionsMenu = () => {
           const calendarFieldMetadataId = availableFieldsForCalendar[0].id;
 
           setRecordIndexViewType(viewType);
-          store.set(coreViewsState.atom, [
-            ...existingCoreViews.filter(
-              (coreView) => coreView.id !== currentView.id,
-            ),
-            {
-              ...currentCoreView,
-              mainGroupByFieldMetadataId: null,
-              type: convertViewTypeToCore(viewType),
-              calendarLayout: ViewCalendarLayout.MONTH,
-              calendarFieldMetadataId,
-            },
-          ]);
 
           loadRecordIndexStates(
             {