chore: import upstream snapshot with attribution

servers/nextjs/app/api/validate-layout-code/route.ts

@@ -0,0 +1,56 @@
+import { NextResponse } from "next/server";
+
+import {
+  LayoutCodeValidationError,
+  validateLayoutCode,
+} from "@/lib/validate-layout-code";
+
+export const dynamic = "force-dynamic";
+
+function invalidResponse(error: string, line?: number, column?: number) {
+  return NextResponse.json(
+    {
+      ok: false,
+      error,
+      ...(line === undefined ? {} : { line }),
+      ...(column === undefined ? {} : { column }),
+    },
+    { status: 400 }
+  );
+}
+
+export async function POST(request: Request) {
+  let payload: unknown;
+  try {
+    payload = await request.json();
+  } catch {
+    return invalidResponse("Request body must be valid JSON");
+  }
+
+  const layoutCode = (payload as { layout_code?: unknown })?.layout_code;
+  if (typeof layoutCode !== "string") {
+    return invalidResponse("layout_code must be a string");
+  }
+
+  try {
+    const validated = validateLayoutCode(layoutCode);
+    return NextResponse.json({
+      ok: true,
+      layout_code: validated.layout_code,
+      layoutId: validated.layoutId,
+      layoutName: validated.layoutName,
+      layoutDescription: validated.layoutDescription,
+      schemaJSON: validated.schemaJSON,
+    });
+  } catch (error) {
+    if (error instanceof LayoutCodeValidationError) {
+      return invalidResponse(error.message, error.line, error.column);
+    }
+
+    console.error("[validate-layout-code] unexpected error", error);
+    return NextResponse.json(
+      { ok: false, error: "Failed to validate layout code" },
+      { status: 500 }
+    );
+  }
+}