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/admin-ads.ts

@@ -0,0 +1,84 @@
+"use server";
+
+import { revalidatePath } from "next/cache";
+import { redirect } from "next/navigation";
+import { requireStaff } from "@/lib/admin/guard";
+import { prisma } from "@/lib/prisma";
+import { logStaffActivity } from "@/lib/services/staff-activity";
+
+// CRUD for website advertisements (website_ads). Emulator does not own this
+// table; it only stores an image URL rendered in the site layout/widgets.
+
+export async function createAd(formData: FormData): Promise<void> {
+  const staff = await requireStaff();
+  const image = String(formData.get("image") ?? "").trim().slice(0, 255);
+  if (!image) return;
+
+  const now = new Date();
+  try {
+    const ad = await prisma.websiteAds.create({
+      data: { image, createdAt: now, updatedAt: now },
+    });
+    await logStaffActivity({
+      staffId: staff.id,
+      action: "ad_create",
+      description: `Created advertisement #${ad.id} (${image})`,
+      targetType: "website_ad",
+      targetId: Number(ad.id),
+    });
+  } catch {
+    // DB error — page re-renders unchanged.
+    revalidatePath("/admin/ads");
+    return;
+  }
+  redirect("/admin/ads");
+}
+
+export async function updateAd(formData: FormData): Promise<void> {
+  const staff = await requireStaff();
+  const raw = String(formData.get("id") ?? "");
+  if (!/^\d+$/.test(raw)) return;
+  const id = BigInt(raw);
+  const image = String(formData.get("image") ?? "").trim().slice(0, 255);
+  if (!image) return;
+
+  try {
+    await prisma.websiteAds.update({
+      where: { id },
+      data: { image, updatedAt: new Date() },
+    });
+    await logStaffActivity({
+      staffId: staff.id,
+      action: "ad_update",
+      description: `Updated advertisement #${id} (${image})`,
+      targetType: "website_ad",
+      targetId: Number(id),
+    });
+  } catch {
+    // Not found or DB error — ignore.
+    revalidatePath(`/admin/ads/${id}`);
+    return;
+  }
+  redirect("/admin/ads");
+}
+
+export async function deleteAd(formData: FormData): Promise<void> {
+  const staff = await requireStaff();
+  const raw = String(formData.get("id") ?? "");
+  if (!/^\d+$/.test(raw)) return;
+  const id = BigInt(raw);
+
+  try {
+    await prisma.websiteAds.delete({ where: { id } });
+    await logStaffActivity({
+      staffId: staff.id,
+      action: "ad_delete",
+      description: `Deleted advertisement #${id}`,
+      targetType: "website_ad",
+      targetId: Number(id),
+    });
+  } catch {
+    // Not found or DB error — ignore.
+  }
+  redirect("/admin/ads");
+}