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/api/v1/users/me/notification-prefs/route.ts

@@ -13,6 +13,15 @@ const PutSchema = z.object({
   mention: z.boolean().optional(),
   leftoverExpiring: z.boolean().optional(),
   shoppingList: z.boolean().optional(),
+  followEmail: z.boolean().optional(),
+  commentEmail: z.boolean().optional(),
+  replyEmail: z.boolean().optional(),
+  reactionEmail: z.boolean().optional(),
+  ratingEmail: z.boolean().optional(),
+  mentionEmail: z.boolean().optional(),
+  leftoverExpiringEmail: z.boolean().optional(),
+  shoppingListEmail: z.boolean().optional(),
+  weeklyDigestEmail: z.boolean().optional(),
 });
 
 export async function GET() {