Security hardening: 12 improvements across the stack

1. env.ts: APP_KEY placeholder detection with validation
2. schema.prisma: password column widened to varchar(255) for argon2id
3. auth.ts: trustHost restricted to development only
4. next.config.ts: added CSP, HSTS, X-Frame-Options, and other security headers
5. api.ts: CORS restricted to APP_URL instead of wildcard
6. register-form.tsx: migrated from REST API fetch to server action (useActionState)
7. twofactor.ts + 2fa page: TOTP recovery codes (8 one-time codes, generated and displayed)
8. register.ts: password min length 8 + complexity requirements (upper, lower, digit)
9. register.ts + help-tickets.ts + radio-shouts.ts: Zod schema validation
10. rate-limit.ts: improved periodic cleanup with aggressive eviction at 10k buckets
11. guard.ts + admin actions: rate-limited admin actions (30 req/min per staff)
12. help-tickets.ts + radio-shouts.ts: content moderation via moderateOrThrow

next.config.ts

@@ -1,17 +1,54 @@
 import type { NextConfig } from "next";
 import createNextIntlPlugin from "next-intl/plugin";
 
+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=()",
+  },
+  {
+    key: "Content-Security-Policy",
+    value: [
+      "default-src 'self'",
+      "script-src 'self' 'unsafe-eval' 'unsafe-inline' https://challenges.cloudflare.com https://www.google.com/recaptcha/ https://www.gstatic.com/recaptcha/",
+      "style-src 'self' 'unsafe-inline'",
+      "img-src 'self' data: blob: https:",
+      "frame-src 'self' https://challenges.cloudflare.com https://www.google.com/recaptcha/",
+      "connect-src 'self' https: wss:",
+      "font-src 'self' data:",
+      "object-src 'none'",
+      "base-uri 'self'",
+      "form-action 'self'",
+    ].join("; "),
+  },
+];
+
 const nextConfig: NextConfig = {
   // This app lives inside the Laravel repo tree (which has its own lockfiles);
   // pin the Turbopack root so Next doesn't infer a parent directory.
   turbopack: { root: import.meta.dirname },
+  
   // Prisma + the MariaDB driver adapter are native/server-only — keep them out
   // of the bundle (same approach as the habbo-next reference).
   serverExternalPackages: ["@prisma/adapter-mariadb", "mariadb", "@prisma/client"],
+
+  async headers() {
+    return [
+      {
+        source: "/(.*)",
+        headers: securityHeaders,
+      },
+    ];
+  },
 };
 
 // next-intl WITHOUT i18n routing — locale comes from the NEXT_LOCALE cookie via
 // src/i18n/request.ts, so URLs and the access-guard middleware stay unchanged.
 const withNextIntl = createNextIntlPlugin("./src/i18n/request.ts");
 
-export default withNextIntl(nextConfig);
+export default withNextIntl(nextConfig);