fix: cancel pending rAFs on Chat destroy

Author: Algorithm5838

src/lib/components/chat/Chat.svelte

@@ -835,6 +835,10 @@
 			try {
 				clearTimeout(saveControlsTimer);
 				saveControls();
+				cancelAnimationFrame(scrollRAF);
+				cancelAnimationFrame(contentsRAF);
+				scrollRAF = null;
+				contentsRAF = null;
 				if (chatIdProp && !$temporaryChatEnabled) {
 					updateLastReadAt(chatIdProp);
 				}