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/api/v1/admin/reports/[id]/route.ts

@@ -8,7 +8,7 @@ interface RouteContext {
 }
 
 export async function PATCH(req: NextRequest, { params }: RouteContext) {
-  const { session, response } = await requireAdmin();
+  const { session, response } = await requireAdmin({ allowModerator: true });
   if (response) return response;
 
   const { id } = await params;

apps/web/app/api/v1/admin/reports/route.ts

@@ -3,7 +3,7 @@ import { requireAdmin } from "@/lib/api-auth";
 import { db, reports, users, eq, desc } from "@epicure/db";
 
 export async function GET() {
-  const { response } = await requireAdmin();
+  const { response } = await requireAdmin({ allowModerator: true });
   if (response) return response;
 
   const rows = await db