Returns a list of artists similar to the specified artist, each annotated with the logged-in user's relationship to that similar artist (e.g. whether the user is already following them, and their follower counts). It's the "similar artists" list combined with per-user context, rather than plain similarity data.
When to use it: Use this when showing a "Similar Artists" or "You might also like" section on an artist page for a signed-in user, where you need to render follow/unfollow state for each recommended artist inline. If you just need the raw list of similar artists without any user-specific follow state, use the plain similar-artists endpoint (e.g. {id}/similarbytags in the Metadata API) instead — this one is specifically for personalized, user-aware rendering.
