Add captcha support to authentication features

The update includes the implementation of captcha support during the sign-in and sign-up process for user accounts. The process ensures a better level of security against bot-based attacks. Also, the code has been refactored to separate error and success alerts and unnecessary useEffect hooks have been removed. Moreover, some logic concerning the authentication rendering has been simplified.

apps/web/config/auth.config.ts

@@ -5,6 +5,7 @@ import { z } from 'zod';
 const providers: z.ZodType<Provider> = getProviders();
 
 const AuthConfigSchema = z.object({
+  captchaTokenSiteKey: z.string().min(1).optional(),
   providers: z.object({
     password: z.boolean({
       description: 'Enable password authentication.',
@@ -17,6 +18,10 @@ const AuthConfigSchema = z.object({
 });
 
 const authConfig = AuthConfigSchema.parse({
+  // NB: This is a public key, so it's safe to expose.
+  // Copy the value from the Supabase Dashboard.
+  captchaTokenSiteKey: process.env.NEXT_PUBLIC_CAPTCHA_SITE_KEY ?? '',
+
   // NB: Enable the providers below in the Supabase Console
   // in your production project
   providers: {