Apply brand defaults to MJML survey and product buttons

packages/email-renderer/test/survey-brand.test.ts

@@ -0,0 +1,16 @@
+import { expect, test } from "bun:test";
+import { createRequire } from "node:module";
+import type { BlockDocument } from "@wrnexus/blocks";
+import { renderEmail } from "../src/index.ts";
+const compile = createRequire(import.meta.url)("mjml");
+
+test("survey MJML button inherits brand color and preserves safe text fallback", async () => {
+  const document: BlockDocument = { schemaVersion: 1, kind: "email", meta: { subject: "Survey" }, theme: { tokens: {} }, root: { id: "root", type: "layout.email-document", version: 1, props: { width: "600", linkColor: "#a12345" }, styles: {}, slots: { content: [{ id: "survey", type: "content.survey", version: 1, props: { question: "How was your visit?", buttonLabel: "Answer & share", href: "https://example.com/survey" }, styles: {}, slots: {} }] } } };
+  const result = await renderEmail(document, { mjml: true });
+  if (!result.ok) throw new Error("Render failed");
+  expect(result.value.parts.text.content).toContain("How was your visit?\nAnswer & share: https://example.com/survey");
+  const compiled = await compile(result.value.exports!.mjml!, { validationLevel: "strict" });
+  expect(compiled.errors).toEqual([]);
+  expect(compiled.html).toContain("background:#a12345");
+  expect(compiled.html).toContain("Answer & share");
+});