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/MaintenancePage.tsx

@@ -231,7 +231,7 @@ function MaintenanceModal({
         {/* Type selector */}
         <div>
           <label className="block text-sm font-medium text-slate-700 dark:text-slate-300 mb-2">Тип</label>
-          <div className="grid grid-cols-3 gap-2">
+          <div className="grid grid-cols-3 sm:grid-cols-3 gap-2">
             {([
               { id: 'room' as const,    label: 'Номер',   icon: BedDouble },
               { id: 'service' as const, label: 'Услуга',  icon: Wrench },
@@ -362,7 +362,7 @@ export function MaintenancePage() {
   const active   = records.filter(r => r.status !== 'done' && r.status !== 'cancelled')
 
   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>
@@ -378,7 +378,7 @@ export function MaintenancePage() {
       </div>
 
       {/* Stats */}
-      <div className="grid grid-cols-2 lg:grid-cols-4 gap-3">
+      <div className="grid grid-cols-2 md:grid-cols-4 gap-3">
         {[
           { label: 'Всего записей',      value: records.length,                                                                                        cls: '' },
           { label: 'Активных',           value: active.length,                                                                                         cls: 'text-amber-600 dark:text-amber-400' },