Add canoncial links for the changelog

app/changelog/%5Fadmin/layout.tsx

@@ -1,10 +1,15 @@
 import {type ReactNode, Suspense} from 'react';
 import {GET} from 'app/changelog/api/auth/[...nextauth]/route';
+import type {Metadata} from 'next';
 import {getServerSession} from 'next-auth/next';
 
 import LoginButton from 'sentry-docs/components/changelog/loginButton';
 import NextAuthSessionProvider from 'sentry-docs/components/nextAuthSessionProvider';
 
+export const metadata: Metadata = {
+  robots: 'noindex, nofollow',
+};
+
 export default async function Layout({children}: {children: ReactNode}) {
   const session = await getServerSession(GET);
   let content = (

app/changelog/[slug]/page.tsx

@@ -37,6 +37,9 @@ export async function generateMetadata(
   return {
     title: changelog?.title,
     description: changelog?.summary,
+    alternates: {
+      canonical: `https://sentry.io/changelog/${params.slug}`,
+    },
     openGraph: {
       images: changelog?.image || (await parent).openGraph?.images,
     },

app/changelog/layout.tsx

@@ -18,6 +18,7 @@ const rubik = Rubik({
 
 export const metadata: Metadata = {
   title: {template: '%s | Sentry Changelog', default: 'Changelog'},
+  metadataBase: new URL('https://sentry.io/changelog/'),
 };
 
 export default function ChangelogLayout({children}: {children: ReactNode}) {

app/changelog/page.tsx

@@ -189,6 +189,9 @@ export function generateMetadata(): Metadata {
   return {
     description:
       'Stay up to date on everything big and small, from product updates to SDK changes with the Sentry Changelog.',
+    alternates: {
+      canonical: `https://sentry.io/changelog/`,
+    },
     other: {
       'sentry-trace': `${Sentry.getActiveSpan()?.toTraceparent()}`,
     },