Add security middleware, audit log, alerts, PayPal, cron, radio + apps

Security (launch blockers):
- src/middleware.ts (edge): forwards x-pathname + real client IP.
- access-guard.ts (Node, from root layout): routes non-staff to /maintenance
  when maintenance mode is on, banned users to /banned. New /banned + /maintenance
  pages (the consumers the admin toggle was missing). Admin layout enforces
  force_staff_2fa before /admin.
- staff-activity.ts audit log wired into ban/lift/give-currency/set-rank actions.

Infra (parallel agents): alert service (alert_logs + Discord embed + email),
PayPal top-up (create/capture API routes + /shop/topup), cron worker
(scripts/jobs-worker.ts via croner: emulator-ping->alert, maintenance-check,
bans-cleanup), social connections page, admin radio settings/banners/ranks.
Public radio subsystem: /radio (+schedule, shouts+post, contests, giveaways,
apply, leaderboard) and /apply/staff + /apply/team submission forms. Radio nav
link added. .env.example documents the new optional vars.

(radio song-requests dropped: its table is a stub in AtomCMS — columns added by
un-modeled alter-migrations.)

Verified: tsc exit 0, vitest 48/48, next build exit 0 (82 page routes).

src/app/layout.tsx

@@ -6,6 +6,7 @@ import { SiteFooter } from "@/components/site-footer";
 import { SiteHeader } from "@/components/site-header";
 import { ThemeVars } from "@/components/theme-vars";
 import { TopHeader } from "@/components/top-header";
+import { enforceSiteAccess } from "@/lib/access-guard";
 import "./globals.css";
 
 const nunito = Nunito({
@@ -20,7 +21,8 @@ export const metadata: Metadata = {
   description: "AtomCMS — retro hotel CMS (Next.js conversion)",
 };
 
-export default function RootLayout({ children }: { children: ReactNode }) {
+export default async function RootLayout({ children }: { children: ReactNode }) {
+  await enforceSiteAccess();
   return (
     <html lang="en" className={`app ${nunito.variable}`}>
       <body