Next.js Supabase V3 (#463)

Version 3 of the kit:
- Radix UI replaced with Base UI (using the Shadcn UI patterns)
- next-intl replaces react-i18next
- enhanceAction deprecated; usage moved to next-safe-action
- main layout now wrapped with [locale] path segment
- Teams only mode
- Layout updates
- Zod v4
- Next.js 16.2
- Typescript 6
- All other dependencies updated
- Removed deprecated Edge CSRF
- Dynamic Github Action runner

apps/web/app/[locale]/docs/_components/docs-header.tsx

@@ -0,0 +1,36 @@
+import Link from 'next/link';
+
+import { Header } from '@kit/ui/marketing';
+import { Separator } from '@kit/ui/separator';
+import { Trans } from '@kit/ui/trans';
+
+import { AppLogo } from '~/components/app-logo';
+
+import { DocsBackButton } from './docs-back-button';
+
+export function DocsHeader() {
+  return (
+    <Header
+      logo={
+        <div className={'flex w-full flex-1 justify-between'}>
+          <div className="flex items-center gap-x-4">
+            <AppLogo href="/" />
+
+            <Separator orientation="vertical" />
+
+            <Link
+              href="/help"
+              className="font-semibold tracking-tight hover:underline"
+            >
+              <Trans i18nKey="marketing.documentation" />
+            </Link>
+          </div>
+
+          <DocsBackButton />
+        </div>
+      }
+      centered={false}
+      className="border-border/50 border-b px-4"
+    />
+  );
+}