feat: per-category email prefs, admin ops webhooks, per-user feature toggles (v0.61.0)

- Notification email preferences: every push category (follow, comment,
  reply, reaction, rating, mention, leftoverExpiring, shoppingList) now has
  an independent email toggle, plus a Weekly Digest toggle. Previously email
  sent unconditionally whenever the recipient had one; now gated the same
  way push already was. The weekly-digest cron route excludes opted-out
  users.

- Admin-only site-wide webhooks (Admin → Webhooks): new signups, support
  tickets, and reports filed can now fire an HMAC-signed HTTP webhook
  (Slack/Discord/ops alerting), independent of the existing per-user
  webhooks (which stay scoped to a user's own recipe/meal-plan/shopping-list
  events). Signing/delivery logic factored into lib/webhook-delivery.ts and
  shared by both dispatchers instead of duplicated.

- Settings → Features: users can hide Nutrition, Pantry, Meal Plan,
  Shopping Lists, Collections, or Messages from their own nav. Purely
  cosmetic — hidden pages stay reachable by direct link, nothing is
  access-restricted.

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

apps/web/app/(app)/settings/features/page.tsx

@@ -0,0 +1,24 @@
+import type { Metadata } from "next";
+import { headers } from "next/headers";
+import { auth } from "@/lib/auth/server";
+import { FeatureTogglesForm } from "@/components/settings/feature-toggles-form";
+import { getMessages } from "@/lib/i18n/server";
+
+export const metadata: Metadata = {};
+
+export default async function FeaturesSettingsPage() {
+  const session = await auth.api.getSession({ headers: await headers() });
+  const m = getMessages((session?.user as { locale?: string })?.locale);
+
+  return (
+    <section className="rounded-xl border p-6 space-y-4">
+      <div>
+        <h2 className="font-semibold text-lg">{m.settingsForm.featureToggles.title}</h2>
+        <p className="text-sm text-muted-foreground mt-1">
+          {m.settingsForm.featureToggles.description}
+        </p>
+      </div>
+      <FeatureTogglesForm />
+    </section>
+  );
+}