Add a twerk emote and drop the front flip

The twerk was measured from a 3D preview with the new emote capture tool, then made left/right
symmetric so it sways evenly instead of leaning to one side. The front flip is removed because it
plays wrongly with the new emote library.

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

src/main/java/org/saturnclient/cosmetics/Emotes.java

@@ -17,7 +17,7 @@ import org.saturnclient.ui.Utils;
  */
 public class Emotes {
     private static final List<String> IDS = List.of("tpose", "back_flip", "facepalm", "cry", "giga_chad",
-            "front_flip");
+            "twerk");
 
     private static final EmoteRegistry REGISTRY = new EmoteRegistry();