Add dark mode, i18n, messenger/moderation/verify, admin CRUD parity

Web-tier features completing the AtomCMS→Next.js conversion (slice 2):

UI/UX:
- Dark mode: html.dark CSS-var overrides + ThemeSwitcher (localStorage,
  no-flash boot script) wired into the nav.
- i18n (next-intl, cookie-based / no URL routing): en + it catalogs,
  request.ts, provider in root layout, LanguageSwitcher; shell (nav,
  header, footer) fully translated. URLs + access-guard unchanged.
- globals.css: --muted/--border aliases used across admin pages.

User features:
- /messages: offline messages + friend-request accept (server action
  re-reads session, two directional rows, idempotent).
- Email verification: signed-token /verify route + sendVerification wired
  into register (best-effort, never blocks signup).
- Article reactions: toggle UI on news/[slug] + server action.
- Content moderation service (website_wordfilter + optional OpenAI
  moderations, fail-open) wired into article comments + guestbook.

Admin CRUD parity (Filament replacement):
- /admin/shop (+ new/[id]) packages CRUD + read-only orders.
- /admin/transactions read-only PayPal log.
- /admin/permissions, /admin/tags, /admin/ads (+ new/[id]),
  /admin/help-questions (+ new/[id]), /admin/radio/history,
  /admin/users/[id]/edit. All gated by requireStaff + logStaffActivity.

Verified: tsc 0, vitest 48/48, next build 0 (all routes incl. new
admin CRUD + /messages + /verify).

src/actions/article-comments.ts

@@ -3,6 +3,7 @@
 import { revalidatePath } from "next/cache";
 import { auth } from "@/lib/auth";
 import { prisma } from "@/lib/prisma";
+import { isAllowed } from "@/lib/services/moderation";
 
 // website_article_comments.comment is VARCHAR(255); keep the write within bounds.
 const COMMENT_MAX = 255;
@@ -23,6 +24,9 @@ export async function postComment(formData: FormData): Promise<void> {
   const comment = String(formData.get("comment") ?? "").trim().slice(0, COMMENT_MAX);
   if (!comment) return;
 
+  // Block filtered/AI-flagged content before it touches the DB (fail-open).
+  if (!(await isAllowed(comment)).ok) return;
+
   const articleIdRaw = String(formData.get("articleId") ?? "").trim();
   if (!/^\d+$/.test(articleIdRaw)) return;