Fix site crash by restoring next-intl plugin and lost next.config.ts options

Recent optimization commits accidentally gutted next.config.ts, removing
the createNextIntlPlugin wrapper. This caused every page to crash at
runtime with 'Couldn't find next-intl config file', showing the error
page after a successful build.

Restores:
- next-intl plugin (./src/i18n/request.ts)
- Security headers (HSTS, X-Frame-Options, nosniff, etc.)
- Redirects from /admin/import/* to /admin/studio/*
- Cache headers for /assets and /images, AVIF/WebP image formats
- compress and productionBrowserSourceMaps

Keeps recent improvements: reactStrictMode and optimizePackageImports.

next.config.ts

@@ -1,5 +1,6 @@
 import { execSync } from "node:child_process";
 import type { NextConfig } from "next";
+import createNextIntlPlugin from "next-intl/plugin";
 
 const getGitCommit = () => {
 	try {
@@ -9,13 +10,129 @@ const getGitCommit = () => {
 	}
 };
 
+const securityHeaders = [
+	{ key: "X-DNS-Prefetch-Control", value: "on" },
+	{
+		key: "Strict-Transport-Security",
+		value: "max-age=63072000; includeSubDomains; preload",
+	},
+	{ key: "X-Frame-Options", value: "DENY" },
+	{ key: "X-Content-Type-Options", value: "nosniff" },
+	{ key: "Referrer-Policy", value: "strict-origin-when-cross-origin" },
+	{
+		key: "Permissions-Policy",
+		value: "camera=(), microphone=(), geolocation=(), interest-cohort=()",
+	},
+];
+
 const nextConfig: NextConfig = {
 	deploymentId: process.env.NEXT_DEPLOYMENT_ID?.trim() || getGitCommit(),
 	reactStrictMode: true,
-	serverExternalPackages: ["lzma", "sharp"],
+	compress: true,
+	productionBrowserSourceMaps: false,
+	serverExternalPackages: ["lzma", "sharp", "pino", "pino-pretty"],
+
+	async redirects() {
+		return [
+			{
+				source: "/admin/import",
+				destination: "/admin/studio/furni",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/badges",
+				destination: "/admin/studio/badges",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/furni",
+				destination: "/admin/studio/furni",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/furni/upload",
+				destination: "/admin/studio/upload",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/clothing",
+				destination: "/admin/studio/clothing",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/effects",
+				destination: "/admin/studio/effects",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/pets",
+				destination: "/admin/studio/pets",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/clone",
+				destination: "/admin/studio/clone",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/sync",
+				destination: "/admin/studio/sync",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/repair-icons",
+				destination: "/admin/studio/repair-icons",
+				permanent: true,
+			},
+			{
+				source: "/admin/import/audit",
+				destination: "/admin/studio/audit",
+				permanent: true,
+			},
+		];
+	},
+
+	turbopack: {
+		ignoreIssue: [
+			{
+				path: "**/src/lib/**",
+			},
+		],
+	},
+
 	experimental: {
 		optimizePackageImports: ["lucide-react", "date-fns"],
+		useTypeScriptCli: true,
+		hideLogsAfterAbort: true,
+	},
+
+	images: {
+		formats: ["image/avif", "image/webp"],
+	},
+
+	async headers() {
+		return [
+			{
+				source: "/(.*)",
+				headers: securityHeaders,
+			},
+			{
+				source: "/assets/(.*)",
+				headers: [
+					{
+						key: "Cache-Control",
+						value: "public, max-age=31536000, immutable",
+					},
+				],
+			},
+			{
+				source: "/images/(.*)",
+				headers: [{ key: "Cache-Control", value: "public, max-age=86400" }],
+			},
+		];
 	},
 };
 
-export default nextConfig;
+const withNextIntl = createNextIntlPlugin("./src/i18n/request.ts");
+
+export default withNextIntl(nextConfig);