refac

src/lib/components/chat/Chat.svelte

@@ -200,6 +200,11 @@
 			window.setTimeout(() => scrollToBottom(), 0);
 
 			await tick();
+			
+			// Mark chat read when initially loading it
+			if (chatIdProp && !$temporaryChatEnabled) {
+				updateLastReadAt(chatIdProp);
+			}
 
 			// Process any queued requests if the chat is idle
 			const lastMessage = history.currentId ? history.messages[history.currentId] : null;
@@ -403,6 +408,13 @@
 		saveChatHandler(_chatId, history);
 	};
 
+	const updateLastReadAt = (id) => {
+		$socket?.emit('events:chat', {
+			chat_id: id,
+			data: { type: 'last_read_at' }
+		});
+	};
+
 	const terminalEventHandler = (type: string, data: any) => {
 		if (type === 'terminal:display_file') {
 			if (!data?.path) return;
@@ -768,6 +780,9 @@
 
 		return () => {
 			try {
+				if (chatIdProp && !$temporaryChatEnabled) {
+					updateLastReadAt(chatIdProp);
+				}
 				pageSubscribe();
 				showControlsSubscribe();
 				selectedFolderSubscribe();

src/lib/components/layout/Sidebar.svelte

@@ -1290,6 +1290,8 @@
 												id={chat.id}
 												title={chat.title}
 												createdAt={chat.created_at}
+												updatedAt={chat.updated_at}
+												lastReadAt={chat.last_read_at}
 												{shiftKey}
 												selected={selectedChatId === chat.id}
 												on:select={() => {
@@ -1351,6 +1353,8 @@
 										id={chat.id}
 										title={chat.title}
 										createdAt={chat.created_at}
+										updatedAt={chat.updated_at}
+										lastReadAt={chat.last_read_at}
 										{shiftKey}
 										selected={selectedChatId === chat.id}
 										on:select={() => {

src/lib/components/layout/Sidebar/ChatItem.svelte

@@ -50,6 +50,8 @@
 	export let id;
 	export let title;
 	export let createdAt: number | null = null;
+	export let updatedAt: number | null = null;
+	export let lastReadAt: number | null = null;
 
 	export let selected = false;
 	export let shiftKey = false;
@@ -79,6 +81,11 @@
 
 	let mouseOver = false;
 
+	$: unread =
+		id !== $chatId &&
+		!$activeChatIds.has(id) &&
+		(lastReadAt === null || (updatedAt !== null && updatedAt > lastReadAt));
+
 	const loadChat = async () => {
 		if (!chat) {
 			draggable = false;
@@ -435,6 +442,10 @@
 				if ($mobile) {
 					showSidebar.set(false);
 				}
+
+				// Optimistically mark as read in UI when clicked
+				unread = false;
+				lastReadAt = Date.now() / 1000;
 			}}
 			on:dblclick={async (e) => {
 				e.preventDefault();
@@ -460,7 +471,17 @@
 			{/if}
 
 			<div class="flex self-center flex-1 w-full min-w-0">
-				<div dir="auto" class="text-left self-center overflow-hidden w-full h-[20px] truncate">
+				{#if unread}
+					<div class="shrink-0 self-center pr-2.5 flex transition-opacity duration-300">
+						<div class="size-1.5 bg-sky-500 rounded-full" />
+					</div>
+				{/if}
+				<div
+					dir="auto"
+					class="text-left self-center overflow-hidden w-full h-[20px] truncate {unread
+						? 'font-medium text-gray-900 dark:text-gray-100'
+						: ''}"
+				>
 					{title}
 				</div>
 			</div>

src/lib/components/layout/Sidebar/RecursiveFolder.svelte

@@ -682,6 +682,8 @@
 							id={chat.id}
 							title={chat.title}
 							createdAt={chat.created_at}
+							updatedAt={chat.updated_at}
+							lastReadAt={chat.last_read_at}
 							{shiftKey}
 							on:change={(e) => {
 								dispatch('change', e.detail);