Make Find One with autojoin

https://orkhan.gitbook.io/typeorm/docs/find-options

```ts
export async function getOneAndJoin(
store: Store,
entityConstructor: EntityConstructor,
id: string,
relations: FindOptionsRelations
): Promise {
const where: FindOptionsWhere = { id } as FindOptionsWhere
return store.findOne(entityConstructor, { relations, where })
}
```

Start with the linked Find Options documentation and inspect Store.findOne alongside the getOneAndJoin example shown in the issue. Trace how relations and where are passed into Find One, then verify that the requested autojoin behavior works through the repository's existing checks.

Written by the indexing model from the issue text.