Formalize CreateFlowState + validate draft/publish API payloads

lib/server/validation/zodHttp.ts

@@ -0,0 +1,17 @@
+import { NextResponse } from "next/server";
+import type { ZodError } from "zod";
+
+export function jsonFromZodError(error: ZodError): NextResponse {
+  const issue = error.issues[0];
+  const message = issue?.message ?? "Validation failed";
+  return NextResponse.json(
+    {
+      error: {
+        code: "validation_error",
+        message,
+      },
+      details: error.flatten(),
+    },
+    { status: 400 },
+  );
+}