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/app/admin/help-questions/[id]/page.tsx

@@ -0,0 +1,85 @@
+import Link from "next/link";
+import { notFound } from "next/navigation";
+import { deleteHelpQuestion, updateHelpQuestion } from "@/actions/admin-help";
+import { prisma } from "@/lib/prisma";
+
+export const dynamic = "force-dynamic";
+
+export default async function EditHelpQuestion({
+  params,
+}: {
+  params: Promise<{ id: string }>;
+}) {
+  const { id } = await params;
+  let entry: Awaited<
+    ReturnType<typeof prisma.websiteHelpCenterCategories.findUnique>
+  > = null;
+  try {
+    entry = await prisma.websiteHelpCenterCategories.findUnique({
+      where: { id: BigInt(id) },
+    });
+  } catch {
+    notFound();
+  }
+  if (!entry) notFound();
+
+  return (
+    <main>
+      <p className="muted">
+        <Link href="/admin/help-questions">← Help Center</Link>
+      </p>
+      <h1>Edit help-center entry</h1>
+      <form action={updateHelpQuestion} className="card" style={{ display: "grid", gap: "0.6rem" }}>
+        <input type="hidden" name="id" value={String(entry.id)} />
+        <input name="name" defaultValue={entry.name} placeholder="Name / title" required maxLength={255} />
+        <textarea name="content" defaultValue={entry.content} placeholder="Content" rows={6} required />
+        <input
+          name="position"
+          type="number"
+          min={1}
+          defaultValue={entry.position}
+          placeholder="Position"
+        />
+        <input
+          name="imageUrl"
+          defaultValue={entry.imageUrl ?? ""}
+          placeholder="Image URL (optional)"
+          maxLength={255}
+        />
+        <input
+          name="buttonText"
+          defaultValue={entry.buttonText ?? ""}
+          placeholder="Button text (optional)"
+          maxLength={255}
+        />
+        <input
+          name="buttonUrl"
+          defaultValue={entry.buttonUrl ?? ""}
+          placeholder="Button URL (optional)"
+          maxLength={255}
+        />
+        <label style={{ display: "flex", gap: "0.4rem", alignItems: "center" }}>
+          Button color
+          <input name="buttonColor" type="color" defaultValue={entry.buttonColor} />
+        </label>
+        <label style={{ display: "flex", gap: "0.4rem", alignItems: "center" }}>
+          Button border color
+          <input name="buttonBorderColor" type="color" defaultValue={entry.buttonBorderColor} />
+        </label>
+        <label style={{ display: "flex", gap: "0.4rem", alignItems: "center" }}>
+          <input name="smallBox" type="checkbox" value="1" defaultChecked={entry.smallBox} />
+          Small box
+        </label>
+        <button type="submit" className="btn btn-primary">
+          Save
+        </button>
+      </form>
+      <form action={deleteHelpQuestion} style={{ marginTop: "1rem" }}>
+        <input type="hidden" name="id" value={String(entry.id)} />
+        <button type="submit" className="btn btn-danger">
+          Delete entry
+        </button>
+      </form>
+    </main>
+  );
+}