fix(webui): name temporary chats from first message

webui/src/lib/temporary-chat.ts

@@ -2,6 +2,15 @@ import type { ChatSummary } from "./types";
 
 const WEBSOCKET_SESSION_KEY_PREFIX = "websocket:";
 
+export function deriveTemporaryChatTitle(
+  firstMessage: string | undefined,
+  fallback: string,
+): string {
+  const oneLine = firstMessage?.replace(/\s+/g, " ").trim() ?? "";
+  if (!oneLine) return fallback;
+  return oneLine.length > 60 ? `${oneLine.slice(0, 57)}…` : oneLine;
+}
+
 export function createTemporaryChatSession(chatId: string): ChatSummary {
   const now = new Date().toISOString();
   return {