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/views/hooks/internal/usePerformViewFieldGroupAPIPersist.ts

@@ -6,7 +6,6 @@ import { useSnackBar } from '@/ui/feedback/snack-bar-manager/hooks/useSnackBar';
 import { CREATE_MANY_CORE_VIEW_FIELD_GROUPS } from '@/views/graphql/mutations/createManyCoreViewFieldGroups';
 import { DELETE_CORE_VIEW_FIELD_GROUP } from '@/views/graphql/mutations/deleteCoreViewFieldGroup';
 import { UPDATE_CORE_VIEW_FIELD_GROUP } from '@/views/graphql/mutations/updateCoreViewFieldGroup';
-import { useTriggerViewFieldGroupOptimisticEffect } from '@/views/optimistic-effects/hooks/useTriggerViewFieldGroupOptimisticEffect';
 import { useMutation } from '@apollo/client/react';
 import { CombinedGraphQLErrors } from '@apollo/client/errors';
 import { t } from '@lingui/core/macro';
@@ -32,9 +31,6 @@ type DeleteCoreViewFieldGroupMutationResult = {
 };
 
 export const usePerformViewFieldGroupAPIPersist = () => {
-  const { triggerViewFieldGroupOptimisticEffect } =
-    useTriggerViewFieldGroupOptimisticEffect();
-
   const [createManyCoreViewFieldGroupsMutation] = useMutation<
     CreateManyCoreViewFieldGroupsMutationResult,
     MutationCreateManyCoreViewFieldGroupsArgs
@@ -70,16 +66,6 @@ export const usePerformViewFieldGroupAPIPersist = () => {
       try {
         const result = await createManyCoreViewFieldGroupsMutation({
           variables: createCoreViewFieldGroupInputs,
-          update: (_cache, { data }) => {
-            const createdViewFieldGroups = data?.createManyCoreViewFieldGroups;
-            if (!isDefined(createdViewFieldGroups)) {
-              return;
-            }
-
-            triggerViewFieldGroupOptimisticEffect({
-              createdViewFieldGroups,
-            });
-          },
         });
 
         return {
@@ -103,7 +89,6 @@ export const usePerformViewFieldGroupAPIPersist = () => {
       }
     },
     [
-      triggerViewFieldGroupOptimisticEffect,
       createManyCoreViewFieldGroupsMutation,
       handleMetadataError,
       enqueueErrorSnackBar,
@@ -128,16 +113,6 @@ export const usePerformViewFieldGroupAPIPersist = () => {
           updateCoreViewFieldGroupInputs.map((variables) =>
             updateCoreViewFieldGroupMutation({
               variables,
-              update: (_cache, { data }) => {
-                const updatedViewFieldGroup = data?.updateCoreViewFieldGroup;
-                if (!isDefined(updatedViewFieldGroup)) {
-                  return;
-                }
-
-                triggerViewFieldGroupOptimisticEffect({
-                  updatedViewFieldGroups: [updatedViewFieldGroup],
-                });
-              },
             }),
           ),
         );
@@ -165,7 +140,6 @@ export const usePerformViewFieldGroupAPIPersist = () => {
       }
     },
     [
-      triggerViewFieldGroupOptimisticEffect,
       updateCoreViewFieldGroupMutation,
       handleMetadataError,
       enqueueErrorSnackBar,
@@ -190,16 +164,6 @@ export const usePerformViewFieldGroupAPIPersist = () => {
           deleteCoreViewFieldGroupInputs.map((variables) =>
             deleteCoreViewFieldGroupMutation({
               variables,
-              update: (_cache, { data }) => {
-                const deletedViewFieldGroup = data?.deleteCoreViewFieldGroup;
-                if (!isDefined(deletedViewFieldGroup)) {
-                  return;
-                }
-
-                triggerViewFieldGroupOptimisticEffect({
-                  deletedViewFieldGroups: [deletedViewFieldGroup],
-                });
-              },
             }),
           ),
         );
@@ -227,7 +191,6 @@ export const usePerformViewFieldGroupAPIPersist = () => {
       }
     },
     [
-      triggerViewFieldGroupOptimisticEffect,
       deleteCoreViewFieldGroupMutation,
       handleMetadataError,
       enqueueErrorSnackBar,