AI-suggested segments for a time entry, as bare ids.

For clients that mirror the matter tree locally — see SuggestedSegmentsResponse. Returns an empty list when no time_entry_id is given (the create-entry dialog has no entry to suggest against yet).

Only segments the user may still assign are returned — a detection recorded before its matter closed, or before the matter was restricted away from them, is dropped here rather than left for the client's mirror to catch. A matter the user is a participant of ranks ahead of an equal score on one they are not, with the same factor segment detection uses.