refac: title gen should only run once

src/lib/components/chat/Chat.svelte

@@ -990,7 +990,7 @@
 			scrollToBottom();
 		}
 
-		if (messages.length == 2 && messages.at(1).content !== '') {
+		if (messages.length == 2 && messages.at(1).content !== '' && selectedModels[0] === model.id) {
 			window.history.replaceState(history.state, '', `/c/${_chatId}`);
 			const _title = await generateChatTitle(userPrompt);
 			await setChatTitle(_chatId, _title);
@@ -1252,7 +1252,7 @@
 			scrollToBottom();
 		}
 
-		if (messages.length == 2) {
+		if (messages.length == 2 && selectedModels[0] === model.id) {
 			window.history.replaceState(history.state, '', `/c/${_chatId}`);
 
 			const _title = await generateChatTitle(userPrompt);