perf: O(1) field checks in UserMessage and MultiResponseMessages

Author: Algorithm5838

src/lib/components/chat/Messages/MultiResponseMessages.svelte

@@ -64,9 +64,11 @@
 	$: if (history.messages) {
 		const source = history.messages[messageId];
 		if (source) {
-			if (message.content !== source.content || message.done !== source.done) {
-				message = structuredClone(source);
-			} else if (JSON.stringify(message) !== JSON.stringify(source)) {
+			if (
+				message.content    !== source.content    ||
+				message.done       !== source.done       ||
+				message.annotation !== source.annotation
+			) {
 				message = structuredClone(source);
 			}
 		}

src/lib/components/chat/Messages/UserMessage.svelte

@@ -56,9 +56,7 @@
 	$: if (history.messages) {
 		const source = history.messages[messageId];
 		if (source) {
-			if (message.content !== source.content) {
-				message = structuredClone(source);
-			} else if (JSON.stringify(message) !== JSON.stringify(source)) {
+			if (message.content !== source.content || message.files !== source.files) {
 				message = structuredClone(source);
 			}
 		}