fix: desktop nav ignored feature toggles; add chatbots toggle (v0.62.0)

Feature toggles (Settings -> Features) were filtered into
visibleNavItems but the desktop horizontal nav still mapped over the
raw NAV_ITEMS list, so hiding a feature only worked on mobile. Both
nav renders now read the same filtered list.

Also adds a Chatbots toggle covering the recipe cooking-chat panel
and the recipe-list cooking assistant, wired end-to-end (schema,
migration, feature-prefs lib, API route, settings form, i18n,
openapi).

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

apps/web/messages/en.json

@@ -1428,7 +1428,9 @@
       "collections": "Collections",
       "collectionsDescription": "Organize recipes into collections.",
       "messages": "Messages",
-      "messagesDescription": "Direct messages with other cooks."
+      "messagesDescription": "Direct messages with other cooks.",
+      "chatbots": "Chatbots",
+      "chatbotsDescription": "AI cooking assistant and recipe chat."
     },
     "profile": "Profile",
     "changePhoto": "Change photo",

apps/web/messages/fr.json

@@ -1419,7 +1419,9 @@
       "collections": "Collections",
       "collectionsDescription": "Organisez vos recettes en collections.",
       "messages": "Messages",
-      "messagesDescription": "Messages directs avec d'autres cuisiniers."
+      "messagesDescription": "Messages directs avec d'autres cuisiniers.",
+      "chatbots": "Chatbots",
+      "chatbotsDescription": "Assistant de cuisine et chat sur les recettes."
     },
     "profile": "Profil",
     "changePhoto": "Changer la photo",