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/app/(app)/recipes/page.tsx

@@ -9,6 +9,7 @@ import { RecipesEmptyState } from "@/components/recipe/recipes-empty-state";
 import { RecipesGrid } from "@/components/recipe/recipes-grid";
 import { CookingAssistantPanel } from "@/components/recipe/cooking-assistant-panel";
 import { getMessages } from "@/lib/i18n/server";
+import { getFeaturePrefs } from "@/lib/feature-prefs";
 
 export const metadata: Metadata = {};
 
@@ -40,6 +41,7 @@ export default async function RecipesPage({ searchParams }: { searchParams: Sear
   const session = await auth.api.getSession({ headers: await headers() });
   if (!session) return null;
   const m = getMessages((session.user as { locale?: string }).locale);
+  const featurePrefs = await getFeaturePrefs(session.user.id);
 
   const { q, sort, visibility, difficulty, tag, page: pageParam, batchCook, recipeType } = await searchParams;
   const query = (q ?? "").trim().slice(0, 200);
@@ -160,7 +162,7 @@ export default async function RecipesPage({ searchParams }: { searchParams: Sear
         </div>
       )}
 
-      <CookingAssistantPanel />
+      {featurePrefs.chatbots && <CookingAssistantPanel />}
     </div>
   );
 }