chore: frontend dead code removal and naming cleanup (#18690)

## Summary

- **Delete 10 unused files**: 7 hooks (`useWorkflowRunUnsafe`,
`useGetViewById`, `useCreateViewFieldGroup`, `useDeleteViewFieldGroup`,
`useUpdateViewFieldGroup`, `useCreateManyViewFieldGroups`,
`useMoveViewColumns` + test), 1 component (`SettingsSummaryCard`), 1
utility (`createEventContext`)
- **Rename `objectMetadataItemsState` → `objectMetadataItemsSelector`**
across ~85 files to accurately reflect it is a derived selector (via
`createAtomSelector`), not a base Jotai atom

## Details

### Dead code removed

| Type | Name | Reason |
|------|------|--------|
| Hook | `useWorkflowRunUnsafe` | Never imported — duplicate of
`useWorkflowRun` without schema validation |
| Hook | `useGetViewById` | Never imported — `useViewById` is used
instead |
| Hook | `useCreateViewFieldGroup` | Never imported — CRUD done via
`usePerformViewFieldGroupAPIPersist` |
| Hook | `useDeleteViewFieldGroup` | Same as above |
| Hook | `useUpdateViewFieldGroup` | Same as above |
| Hook | `useCreateManyViewFieldGroups` | Same as above |
| Hook | `useMoveViewColumns` | Only imported by its own test — no
production usage |
| Component | `SettingsSummaryCard` | Never imported anywhere |
| Utility | `createEventContext` | Never imported anywhere |

### Rename

`objectMetadataItemsState` is created via `createAtomSelector` (it
derives from `objectMetadataItemsWithFieldsSelector`), so naming it
`*State` is misleading. Renamed to `objectMetadataItemsSelector` for
consistency with sibling selectors like
`objectMetadataItemsByNamePluralMapSelector`.

packages/twenty-front/src/modules/navigation/hooks/useSetLastVisitedObjectMetadataId.ts

@@ -1,5 +1,5 @@
 import { lastVisitedObjectMetadataItemIdState } from '@/navigation/states/lastVisitedObjectMetadataItemIdState';
-import { objectMetadataItemsState } from '@/object-metadata/states/objectMetadataItemsState';
+import { objectMetadataItemsSelector } from '@/object-metadata/states/objectMetadataItemsSelector';
 import { useCallback } from 'react';
 import { isDefined } from 'twenty-shared/utils';
 import { useStore } from 'jotai';
@@ -8,7 +8,7 @@ export const useSetLastVisitedObjectMetadataId = () => {
   const store = useStore();
   const setLastVisitedObjectMetadataId = useCallback(
     ({ objectMetadataItemId }: { objectMetadataItemId: string }) => {
-      const objectMetadataItems = store.get(objectMetadataItemsState.atom);
+      const objectMetadataItems = store.get(objectMetadataItemsSelector.atom);
 
       const objectMetadataItem = objectMetadataItems.find(
         (item) => item.id === objectMetadataItemId,