fix: prompt from previous chat being used for new one

src/components/Layout.tsx

@@ -239,6 +239,7 @@ export function Layout() {
                             
                             const item = await detaDB.chats.put({
                               description: "New Chat",
+                              prompt: null,
                               totalTokens: 0,
                               createdAt: new Date().toISOString(),
                             }, generateKey())

src/routes/ChatRoute.tsx

@@ -66,8 +66,8 @@ export function ChatRoute() {
   const { chat, setChat } = useChat()
 
   useEffect(() => {
-    if (chat?.prompt) {
-      setPromptKey(chat.prompt)
+    if (chat) {
+      setPromptKey(chat.prompt ?? null)
     }
   }, [chat]);