Fix mobile responsiveness across all pages

- PosPage: rooms list becomes horizontal scroll row on mobile instead of w-56 sidebar
- AvailabilityPage: edit panel stacks below grid on mobile (was fixed w-80 side panel)
- UsersPage roles tab: sidebar stacks above permissions on mobile
- All page containers: p-6 → p-4 md:p-6 (TariffsPage, DiscountsPage, MaintenancePage, ReportsPage, DynamicPricingPage, GuestsPage, LoyaltyPage)
- Stats grids: lg:grid-cols-4 → md:grid-cols-4 (GuestsPage, TariffsPage, DiscountsPage, MaintenancePage, ReportsPage, LoyaltyPage)
- Modal form grids: grid-cols-3 → grid-cols-1 sm:grid-cols-3, grid-cols-5 → grid-cols-3 sm:grid-cols-5, grid-cols-4 → grid-cols-2 sm:grid-cols-4
- PosPage modals: fixed w-80/w-96 → responsive w-[calc(100vw-2rem)] sm:w-80/96

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/pages/DynamicPricingPage.tsx

@@ -772,7 +772,7 @@ export function DynamicPricingPage() {
     setRules(prev => prev.map(r => r.id === id ? { ...r, isActive: !r.isActive } : r))
 
   return (
-    <div className="p-6 space-y-6">
+    <div className="p-4 md:p-6 space-y-6">
       {/* Header */}
       <div className="flex items-center justify-between">
         <div>