Keep identity prompt context fixed

app.js

@@ -2264,14 +2264,13 @@ function trimConversation() {
 
 function promptMessagesForTurn(text) {
   if (!isAppIdentityQuestion(text)) return state.messages;
-  const rest = state.messages.slice(SYSTEM_MESSAGES.length);
   return [
     {
       role: "system",
       content: IDENTITY_SYSTEM_PROMPT,
     },
     ...IDENTITY_PRIMER_MESSAGES,
-    ...rest,
+    { role: "user", content: text },
   ];
 }