fix: restore rectification agent message actions

frontend/src/app/api/rectification/v4/cases/[caseId]/regenerate/route.ts

@@ -0,0 +1,22 @@
+import { NextResponse } from "next/server";
+import { caseActionRequestSchema } from "@/lib/rectification-v4/contracts";
+import { rectificationV4Context, rectificationV4Error, requestBody, routeId } from "../../../_server";
+
+export const runtime = "nodejs";
+
+export async function POST(request: Request, { params }: { params: Promise<{ caseId: string }> }) {
+  try {
+    const body = await requestBody(request, caseActionRequestSchema);
+    const context = await rectificationV4Context();
+    const result = await context.service.regenerateQuestion({
+      ...body,
+      userId: context.userId,
+      caseId: routeId((await params).caseId),
+    });
+    return result
+      ? NextResponse.json(result)
+      : NextResponse.json({ error: "当前问题不能重新生成，请刷新后重试。" }, { status: 409 });
+  } catch (error) {
+    return rectificationV4Error(error);
+  }
+}