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);