fix: disable route prefetching app-wide to avoid spurious requests

Wrap next/link in a shared Link component that ships prefetch=false by
default, so no route is ever prefetched (viewport or hover) anymore, and
drop the DNS prefetch hint. Removes hidden background requests that were
the source of intermittent issues.

src/components/auth/login-form.tsx

@@ -1,6 +1,5 @@
 "use client";
 
-import Link from "next/link";
 import { signIn } from "next-auth/react";
 import { useTranslations } from "next-intl";
 import { type FormEvent, useState } from "react";
@@ -10,6 +9,7 @@ import {
 	CaptchaWidget,
 	readCaptchaToken,
 } from "@/components/auth/captcha-widget";
+import Link from "@/components/link";
 import { signInWithTransientRetry } from "@/lib/auth/sign-in-retry";
 
 export function LoginForm({

src/components/auth/register-form.tsx

@@ -1,12 +1,12 @@
 "use client";
 
 import Image from "next/image";
-import Link from "next/link";
 import Script from "next/script";
 import { signIn } from "next-auth/react";
 import { useTranslations } from "next-intl";
 import { useActionState, useEffect, useRef, useState } from "react";
 import { type RegisterState, register } from "@/actions/register";
+import Link from "@/components/link";
 import { signInWithTransientRetry } from "@/lib/auth/sign-in-retry";
 
 interface RegisterFormProps {