fix(webui): polish session titles and status

webui/src/lib/format.ts

@@ -1,10 +1,35 @@
 import i18n, { currentLocale } from "@/i18n";
 
+const LOW_INFORMATION_TITLE_PREVIEWS = new Set([
+  "hi",
+  "hello",
+  "hey",
+  "hello nano",
+  "hello nanobot",
+  "hi nano",
+  "hi nanobot",
+  "你好",
+  "您好",
+  "嗨",
+  "哈喽",
+  "哈啰",
+  "在吗",
+]);
+
+function isLowInformationTitlePreview(text: string): boolean {
+  const normalized = text.toLowerCase().replace(/[.!?。！？~～\s]+$/g, "").trim();
+  return (
+    normalized.startsWith("/") ||
+    LOW_INFORMATION_TITLE_PREVIEWS.has(normalized)
+  );
+}
+
 /** Truncate the first user message into a chat title. */
 export function deriveTitle(preview: string | undefined, fallback: string): string {
   if (!preview) return fallback;
   const oneLine = preview.replace(/\s+/g, " ").trim();
   if (!oneLine) return fallback;
+  if (isLowInformationTitlePreview(oneLine)) return fallback;
   return oneLine.length > 60 ? `${oneLine.slice(0, 57)}…` : oneLine;
 }
 

webui/src/lib/nanobot-client.ts

@@ -54,7 +54,8 @@ type Unsubscribe = () => void;
 type EventHandler = (ev: InboundEvent) => void;
 type StatusHandler = (status: ConnectionStatus) => void;
 type RuntimeModelHandler = (modelName: string | null, modelPreset?: string | null) => void;
-type SessionUpdateHandler = (chatId: string) => void;
+type SessionUpdateScope = "metadata" | "thread" | string;
+type SessionUpdateHandler = (chatId: string, scope?: SessionUpdateScope) => void;
 
 /** Structured connection-level errors surfaced to the UI.
  *
@@ -364,7 +365,7 @@ export class NanobotClient {
     }
 
     if (parsed.event === "session_updated") {
-      this.emitSessionUpdate(parsed.chat_id);
+      this.emitSessionUpdate(parsed.chat_id, parsed.scope);
       return;
     }
 
@@ -382,9 +383,9 @@ export class NanobotClient {
     }
   }
 
-  private emitSessionUpdate(chatId: string): void {
+  private emitSessionUpdate(chatId: string, scope?: SessionUpdateScope): void {
     for (const handler of this.sessionUpdateHandlers) {
-      handler(chatId);
+      handler(chatId, scope);
     }
   }