feat: moderator-scoped admin access + fix push notifications not displaying (v0.66.0)

Moderator role existed in the schema and was already respected by
comment deletion, but every admin page/route treated moderator
identically to a regular user (403/redirect). Wires it up narrowly:
admin/layout.tsx now lets admin+moderator through and filters the
nav by role, while every admin-only page (users, tiers, settings,
webhooks, insights, etc.) explicitly redirects moderators away via a
new requireFullAdminPage() helper -- the nav filter is UX, this is
the actual gate. Moderators land on Reports and Recipes: reports
GET/PATCH now accept requireAdmin({allowModerator: true}), and a new
PATCH /api/v1/admin/recipes/[id] lets admin+moderator unpublish a
public recipe (flip to private) as a takedown action, audit-logged.

Also found and fixed a real bug while auditing the PWA push pipeline
for a "push click-through" gap: public/sw.js had no `push` event
listener at all, so incoming push messages never displayed anything
-- push was silently non-functional end-to-end despite the
subscribe/send plumbing all working. Added the push listener
(showNotification) and a notificationclick listener that focuses an
existing tab or opens one at the payload's url.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/admin/page.tsx

@@ -6,10 +6,12 @@ import { count, eq, gte, sql } from "@epicure/db";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 import { Users, BookOpen, Sparkles, Image, History, UserPlus, ChefHat, Flag, HardDrive, Webhook, KeyRound } from "lucide-react";
 import { APP_VERSION, CHANGELOG } from "@/lib/changelog";
+import { requireFullAdminPage } from "@/lib/require-admin-page";
 
 export const metadata: Metadata = {};
 
 export default async function AdminPage() {
+  await requireFullAdminPage();
   const currentMonth = new Date().toISOString().slice(0, 7);
   const sevenDaysAgo = new Date(Date.now() - 7 * 24 * 60 * 60 * 1000);