Remove Cloudflare Turnstile integration and replace it with Vercel's BotID for spam protection in the contact form. Update environment variables and dependencies accordingly.

app/instrumentation.client.ts

@@ -0,0 +1,10 @@
+import { initBotId } from "botid/client/core";
+
+initBotId({
+  protect: [
+    {
+      path: "/contact",
+      method: "POST",
+    },
+  ],
+});

app/privacy/page.mdx

@@ -43,6 +43,4 @@ Occasionally, embedded content from third-party services is included in posts, a
 
 ## Fighting Spam
 
-Using [**Cloudflare Turnstile**](https://www.cloudflare.com/products/turnstile/) to fight bot spam on the [contact form](/contact) was an easy choice over seemingly unavoidable alternatives like [reCAPTCHA](https://developers.google.com/recaptcha/).
-
-You can refer to Cloudflare's [privacy policy](https://www.cloudflare.com/privacypolicy/) and [terms of service](https://www.cloudflare.com/website-terms/) for more details. While some information is sent to the Turnstile API about your behavior (on the contact page only), at least you won't be helping a certain internet conglomerate [train their self-driving cars](https://blog.cloudflare.com/moving-from-recaptcha-to-hcaptcha/). 🚗
+Form submissions on this site are protected by Vercel's [BotID](https://vercel.com/blog/introducing-botid) deep analysis. Refer to [Vercel's](https://vercel.com/legal/privacy-policy) and [Kasada's](https://www.kasada.io/privacy-policy/) privacy policies for details.