feat: add turnstile captcha to auth flow (#2703)

packages/tsconfig/process-env.d.ts

@@ -102,6 +102,12 @@ declare namespace NodeJS {
     POSTGRES_PRISMA_URL?: string;
     POSTGRES_URL_NON_POOLING?: string;
 
+    /**
+     * Cloudflare Turnstile environment variables
+     */
+    NEXT_PUBLIC_TURNSTILE_SITE_KEY?: string;
+    NEXT_PRIVATE_TURNSTILE_SECRET_KEY?: string;
+
     /**
      * Google Vertex AI environment variables
      */