Remove Discord and Google OAuth verification from CMS

- Remove Discord + Google OAuth providers from NextAuth config
- Remove social login buttons (Discord/Google) from login form
- Delete link-discord.ts action and discord-verify-form.tsx component
- Simplify verify page to email-only verification flow
- Remove connections settings page and its link from settings
- Clean env.ts, .env, .env.example of Discord/Google client vars
- Remove discordUrl social icon from register, login, and homepage
- Clean translation files: remove continueWithDiscord, continueWithGoogle, connections keys

src/actions/register.ts

@@ -129,11 +129,5 @@ export async function register(
 		return "Could not create the account (is the username unique?)";
 	}
 
-	if (hasEmail) {
-		redirect("/login?registered=1");
-	} else {
-		const { signIn } = await import("@/lib/auth");
-		await signIn("credentials", { username, password, redirect: false });
-		redirect("/verify?method=discord");
-	}
+	redirect("/login?registered=1");
 }