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/lib/feature-prefs.ts

@@ -0,0 +1,19 @@
+import { db, userFeaturePrefs, eq } from "@epicure/db";
+
+export type FeatureKey = "nutrition" | "pantry" | "mealPlan" | "shoppingLists" | "collections" | "messages";
+
+export type FeaturePrefs = Record<FeatureKey, boolean>;
+
+const DEFAULT_PREFS: FeaturePrefs = {
+  nutrition: true, pantry: true, mealPlan: true, shoppingLists: true, collections: true, messages: true,
+};
+
+/** No row yet means every feature defaults to on — same default the DB columns encode. */
+export async function getFeaturePrefs(userId: string): Promise<FeaturePrefs> {
+  const row = await db.query.userFeaturePrefs.findFirst({ where: eq(userFeaturePrefs.userId, userId) });
+  if (!row) return { ...DEFAULT_PREFS };
+  return {
+    nutrition: row.nutrition, pantry: row.pantry, mealPlan: row.mealPlan,
+    shoppingLists: row.shoppingLists, collections: row.collections, messages: row.messages,
+  };
+}