Remove the hosted rooms' old owner mapping

Hosted rooms' instance IDs start with their owner's IMVU account now, so the client asks about their
products as the owner itself, and the mapping from 2100000000 is never used.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

internal/hosted/hosted.go

@@ -645,17 +645,6 @@ func (r *Rooms) getRoom(ctx context.Context, n int64) (*Room, [][3]any, string,
 	return &out.Room, out.Scene.Contents, out.Scene.Hash, nil
 }
 
-// Owner is the IMVU account owning the hosted room the client joined last (0 if none, or not known): the client
-// checks the room's products against it (products.HostedOwner).
-func (r *Rooms) Owner() int64 {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if _, in := r.rooms[r.last]; !in {
-		return 0
-	}
-	return r.owners[r.last]
-}
-
 func (r *Rooms) roomCard(ctx context.Context, n int64) *http.Response {
 	rm, _, _, err := r.getRoom(ctx, n)
 	if err != nil {