New Captcha Package added

packages/captcha/src/providers/custom.ts

@@ -0,0 +1,8 @@
+import type { CaptchaProvider } from "../types.ts";
+
+export function defineCaptchaProvider<T extends CaptchaProvider>(provider: T): T {
+  if (!provider.name) throw new TypeError("Custom CAPTCHA provider requires a stable name");
+  if (!provider.client?.responseField) throw new TypeError("Custom CAPTCHA provider requires client.responseField");
+  if (typeof provider.verify !== "function") throw new TypeError("Custom CAPTCHA provider requires verify()");
+  return provider;
+}