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/app/(site)/page.tsx

@@ -99,11 +99,7 @@ export default async function Home() {
 					<div className="flex items-center gap-1.5 rounded-lg px-2 py-1" style={{
 						background: "color-mix(in srgb, var(--color-text-muted) 4%, transparent)",
 					}}>
-						{discordUrl && (
-							<Link href={discordUrl} target="_blank" rel="noopener noreferrer" className="p-1.5 rounded-lg transition-all duration-200 hover:scale-110 hover:brightness-125" style={{ background: "color-mix(in srgb, #5865F2 12%, transparent)" }}>
-								<Image src="/assets/images/icons/discord.png" alt="Discord" width={18} height={18} unoptimized />
-							</Link>
-						)}
+
 						<LanguageSwitcher />
 						<div className="w-px h-5" style={{ background: "color-mix(in srgb, var(--color-text-muted) 12%, transparent)" }} />
 						<Clock />