Lessons tab replaces the map tab: chapter > island > lesson list with the island quiz beside it

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/components/BottomNav.tsx

@@ -1,9 +1,9 @@
-import { Brain, ShoppingBag, Home, Map, UserRound, type LucideIcon } from 'lucide-react';
+import { Brain, ShoppingBag, Home, BookOpen, UserRound, type LucideIcon } from 'lucide-react';
 import type { TabName } from '@/nav/routes';
 
 const ITEMS: { id: TabName; icon: LucideIcon; label: string }[] = [
   { id: 'home', icon: Home, label: 'خانه' },
-  { id: 'map', icon: Map, label: 'نقشه' },
+  { id: 'lessons', icon: BookOpen, label: 'درس‌ها' },
   { id: 'ask', icon: Brain, label: 'دستیار' },
   { id: 'subscription', icon: ShoppingBag, label: 'بسته‌ها' },
   { id: 'profile', icon: UserRound, label: 'من' },