Favorite Voice

Add a voice to the current workspace’s favorites.

The response is a full VoiceOut and is narrowed exactly as GET /voices/{voice_id} is, so favoriting a voice never reveals locales the read endpoints hide. Note that favoriting a platform voice with no official locale succeeds but that voice will not appear under ?favorites_only=true, which applies the same list restriction.

Favorites are workspace-scoped, not per-user: all members of the workspace see the same favorited set. Idempotent — favoriting a voice that is already favorited succeeds without error. Returns the voice with is_favorite=true. Requires the caller to have at least editor role in the workspace. Returns 404 for a platform voice from a provider that is not available to your account; voices your workspace owns can always be favorited.