fix: expose native session title summaries

internal/workbench/http.ts

@@ -76,7 +76,10 @@ function requireAuthorization(request: Request, options: { snapshot?: unknown; a
 async function nativeSessionList(options: { snapshot?: () => Promise<any>; mode?: WorkbenchMode }, url: URL) {
   const state = await requiredSnapshot(options);
   const owner = text(url.searchParams.get("ownerUserId"));
-  const sessions = Object.values(state.sessions).filter((session: any) => !owner || session.ownerUserId === owner).sort((left: any, right: any) => String(right.updatedAt).localeCompare(String(left.updatedAt)));
+  const sessions = Object.values(state.sessions)
+    .filter((session: any) => !owner || session.ownerUserId === owner)
+    .map((session: any) => ({ ...session, firstUserMessagePreview: firstUserMessagePreview(session.messages) ?? (text(session.firstUserMessagePreview) || null) }))
+    .sort((left: any, right: any) => String(right.updatedAt).localeCompare(String(left.updatedAt)));
   return json(200, { ok: true, status: "ready", sessions, count: sessions.length, mode: options.mode ?? "native-test" });
 }
 async function nativeSessionDetail(options: { snapshot?: () => Promise<any>; mode?: WorkbenchMode }, sessionId: string, messagesOnly: boolean) {
@@ -244,6 +247,16 @@ function nativeEnvelopeMatches(envelope: any, sessionId: string, traceId: string
   return (!sessionId || envelopeSessionId === sessionId) && (!traceId || envelopeTraceId === traceId);
 }
 
+function firstUserMessagePreview(messages: unknown): string | null {
+  if (!Array.isArray(messages)) return null;
+  for (const message of messages) {
+    if (!message || typeof message !== "object" || text((message as any).role) !== "user") continue;
+    const preview = text((message as any).text ?? (message as any).content ?? (message as any).message);
+    if (preview) return preview.slice(0, 240);
+  }
+  return null;
+}
+
 function actorFrom(request: Request, nativeTest: boolean) {
   const id = text(request.headers.get("x-hwlab-actor-id"));
   if (!id && nativeTest) return { id: "usr_native", role: "user" };

internal/workbench/workbench.test.ts

@@ -75,6 +75,34 @@ describe("Workbench Cloud application adapter", () => {
 });
 
 describe("Workbench native HTTP adapter", () => {
+  test("native session list exposes the first user preview for summary-only rail loading", async () => {
+    const app = createWorkbenchHttpApp({
+      async dispatch() { return { ok: true }; },
+      async snapshot() {
+        return {
+          sessions: {
+            ses_title: {
+              sessionId: "ses_title",
+              updatedAt: "2026-07-20T01:00:00.000Z",
+              messages: [{ role: "user", content: "persisted native title", createdAt: "2026-07-20T00:59:00.000Z" }]
+            },
+            ses_empty: { sessionId: "ses_empty", updatedAt: "2026-07-20T00:00:00.000Z", messages: [] }
+          },
+          turns: {}
+        };
+      }
+    });
+
+    const response = await app.fetch(new Request("http://native.test/v1/workbench/sessions"));
+    expect(response.status).toBe(200);
+    expect(await response.json()).toMatchObject({
+      sessions: [
+        { sessionId: "ses_title", firstUserMessagePreview: "persisted native title" },
+        { sessionId: "ses_empty", firstUserMessagePreview: null }
+      ]
+    });
+  });
+
   test("authorizes only the Workbench navigation entry", async () => {
     const app = createWorkbenchHttpApp({
       async dispatch() { return { ok: true }; },