feat(core-shared): add cta block

packages/core-shared/src/payload/blocks/cta.test.ts

@@ -0,0 +1,16 @@
+import { describe, expect, it } from "vitest";
+import { cta } from "./cta";
+
+describe("cta block", () => {
+  it("has slug 'cta'", () => {
+    expect(cta.slug).toBe("cta");
+  });
+
+  it("requires title, buttonLabel, and href", () => {
+    const fieldNames = cta.fields.map((f) => ("name" in f ? f.name : null));
+    expect(fieldNames).toEqual(["title", "buttonLabel", "href"]);
+    cta.fields.forEach((f) => {
+      if ("required" in f) expect(f.required).toBe(true);
+    });
+  });
+});