refactor(twenty-front): unify Favorites and Workspace navigation menu item code (#18697)

## Summary

- Consolidate duplicated Favorites and Workspace navigation menu item
frontend code into a single unified codebase within
`navigation-menu-item/`
- Move all DnD-related code from `navigation/` module into
`navigation-menu-item/display/dnd/`, renaming `workspaceDndKit*` files
to `navigationMenuItemDndKit*`
- Unify duplicated components (DnD providers, DnD hooks, folder
components, orphan items, section shell) using a `NavigationSections`
enum to parameterize section-specific behavior
- Rename residual workspace-prefixed symbols
(`WorkspaceDndKitSortableItem`, `WorkspaceDndKitDroppableSlot`,
`useWorkspaceSectionItems`, etc.) to `navigationMenuItem`-prefixed
equivalents
- Clean `navigation/` module to only contain app-level concerns (drawer
layout, settings, routing)

### Key changes

| Before (duplicated) | After (unified) |
|---|---|
| `FavoritesDndKitProvider` + `WorkspaceDndKitProvider` |
`NavigationMenuItemDndKitProvider` with `section` prop |
| `useFavoritesDndKit` + `useWorkspaceDndKit` |
`useNavigationMenuItemDndKit(section)` |
| `FavoritesFolderItem` + `WorkspaceNavigationMenuItemsFolder` |
`NavigationMenuItemFolder` with `section` prop |
| `FavoritesOrphanItems` | `NavigationMenuItemOrphanItems` with
`section` prop |
| Separate section shells | Shared `NavigationMenuItemSection` with thin
wrappers |
| `WorkspaceDndKitSortableItem` | `NavigationMenuItemSortableItem` |
| `WorkspaceDndKitDroppableSlot` | `NavigationMenuItemDroppableSlot` |
| `useWorkspaceSectionItems` | `useNavigationMenuItemSectionItems` |
| `useWorkspaceFolderOpenState` | `useNavigationMenuItemFolderOpenState`
|

Net result: **~1650 lines deleted** across 51 files.

## Test plan

- [x] `npx nx typecheck twenty-front` passes
- [x] `npx nx lint twenty-front` passes (0 errors)
- [x] `npx nx test twenty-front` passes (763 suites, 4467 tests)
- [ ] Smoke test: Favorites section renders, DnD reorder works, folder
create/rename/delete works
- [ ] Smoke test: Workspace section renders, edit mode works, DnD
reorder works
- [ ] Smoke test: Add-to-navigation from side panel works for both
sections

Made with [Cursor](https://cursor.com)

packages/twenty-front/src/modules/object-metadata/components/WorkspaceSectionListEditModeFallback.tsx

@@ -1,8 +1,8 @@
 import { styled } from '@linaria/react';
 
-import { NavigationDrawerSectionForWorkspaceItemsListReadOnly } from '@/navigation-menu-item/display/sections/components/NavigationDrawerSectionForWorkspaceItemsListReadOnly';
+import { WorkspaceSectionListReadOnly } from '@/navigation-menu-item/display/sections/workspace/components/WorkspaceSectionListReadOnly';
 import { WorkspaceSectionAddMenuItemButton } from '@/navigation-menu-item/edit/components/WorkspaceSectionAddMenuItemButton';
-import type { WorkspaceSectionListDndKitProps } from '@/navigation-menu-item/display/sections/types/WorkspaceSectionListDndKitProps';
+import type { NavigationMenuItemSectionListDndKitProps } from '@/navigation-menu-item/display/sections/types/NavigationMenuItemSectionListDndKitProps';
 import { themeCssVariables } from 'twenty-ui/theme-constants';
 
 const StyledFallback = styled.div`
@@ -12,7 +12,7 @@ const StyledFallback = styled.div`
 `;
 
 type WorkspaceSectionListEditModeFallbackProps = Pick<
-  WorkspaceSectionListDndKitProps,
+  NavigationMenuItemSectionListDndKitProps,
   'filteredItems' | 'folderChildrenById' | 'onActiveObjectMetadataItemClick'
 >;
 
@@ -22,7 +22,7 @@ export const WorkspaceSectionListEditModeFallback = ({
   onActiveObjectMetadataItemClick,
 }: WorkspaceSectionListEditModeFallbackProps) => (
   <StyledFallback>
-    <NavigationDrawerSectionForWorkspaceItemsListReadOnly
+    <WorkspaceSectionListReadOnly
       filteredItems={filteredItems}
       folderChildrenById={folderChildrenById}
       onActiveObjectMetadataItemClick={onActiveObjectMetadataItemClick}