feat: deprecate WorkspaceFavorite in favor of NavigationMenuItem (#18624)

## Summary

- **Removes the entire `modules/favorites/` directory** (~66 files,
~5000 lines deleted) — components, hooks, states, types, utils, tests,
and the favorite-folder-picker sub-module
- **Eliminates the dual-write pattern** where creating a favorite also
created a NavigationMenuItem — all consumers now use
`useCreateNavigationMenuItem` directly
- **Removes `IS_NAVIGATION_MENU_ITEM_EDITING_ENABLED` feature flag
checks** from ~12 files, always taking the NavigationMenuItem code path
- **Cleans up backend dual-writes** in `object-metadata.service.ts` and
`twenty-standard-application.service.ts` that were creating Favorite
records alongside NavigationMenuItems
- **Updates prefetch system** to only load NavigationMenuItems (removes
favorites prefetch effects and states)
- **Cleans up test infrastructure** — updates Storybook decorators, mock
data, and graphql mocks to remove favorites references

### What was intentionally kept
- **Backend entity definitions** (`FavoriteWorkspaceEntity`,
`FavoriteFolderWorkspaceEntity`) — these define the database schema and
need a proper database migration to remove
- **Cascade deletion listeners** — still needed to clean up existing
Favorite data in workspaces that haven't been fully migrated
- **v1.18 migration commands** — needed for workspaces upgrading from
older versions

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/twenty-server/src/engine/workspace-manager/standard-objects-prefill-data/prefill-workspace-favorites.ts

@@ -1,23 +0,0 @@
-import { type EntityManager } from 'typeorm';
-import { v4 } from 'uuid';
-
-const tableName = 'favorite';
-
-export const prefillWorkspaceFavorites = async (
-  viewIds: string[],
-  entityManager: EntityManager,
-  schemaName: string,
-) => {
-  await entityManager
-    .createQueryBuilder()
-    .insert()
-    .into(`${schemaName}.${tableName}`, ['id', 'viewId', 'position'])
-    .values(
-      viewIds.map((viewId, index) => ({
-        id: v4(),
-        viewId,
-        position: index,
-      })),
-    )
-    .execute();
-};