feat(frontend): store lastUserEntry + stepMessages; record user input/choice

frontend/src/shell/SteerInput.tsx

@@ -6,6 +6,7 @@ import { postSteer, createSession } from "../api/sessions";
 import { getSettings, putSettings, type Settings } from "../api/settings";
 import { listWorkspaces } from "../api/workspaces";
 import { listModels } from "../api/models";
+import { useSessionStore } from "../store/sessionStore";
 
 const THINKING_LEVELS = ["low", "medium", "high"] as const;
 
@@ -23,6 +24,7 @@ interface Props {
 export function SteerInput({ sessionId, onSessionCreated, onStop, inputRef }: Props) {
   const [text, setText] = useState("");
   const [busy, setBusy] = useState(false);
+  const setLastUserEntry = useSessionStore((s) => s.setLastUserEntry);
 
   async function submit() {
     const trimmed = text.trim();
@@ -35,6 +37,7 @@ export function SteerInput({ sessionId, onSessionCreated, onStop, inputRef }: Pr
         const { id } = await createSession({ question: trimmed });
         onSessionCreated?.(id);
       }
+      setLastUserEntry({ kind: "input", text: trimmed });
       setText("");
     } finally {
       setBusy(false);

frontend/src/shell/WidgetHost.tsx

@@ -7,6 +7,7 @@ export function WidgetHost({ sessionId }: { sessionId: string | null }) {
   const pending = useSessionStore((s) => s.pendingWidget);
   const clearPending = useSessionStore((s) => s.clearPending);
   const pushToast = useSessionStore((s) => s.pushToast);
+  const setLastUserEntry = useSessionStore((s) => s.setLastUserEntry);
   if (!pending) return null;
   const Renderer = resolve(pending.widget);
   const onRespond = async (r: UiResponse) => {
@@ -25,6 +26,10 @@ export function WidgetHost({ sessionId }: { sessionId: string | null }) {
         return;
       }
     }
+    setLastUserEntry({
+      kind: "choice",
+      text: r.text ?? r.choices?.join(", ") ?? r.decision?.type ?? r.control ?? "(choice)",
+    });
     clearPending();
   };
   return <Renderer descriptor={pending} onRespond={onRespond} />;