Add hotel registration flow on login page and staff users management page

LoginPage:
- Toggle between login and registration mode
- 2-step registration: step 1 (hotel name + legal entity: type ООО/ИП/АО/ПАО/Другое, company name, INN, KPP hidden for ИП, legal address), step 2 (first/last name, email, phone, password with strength indicator, confirm)
- Step indicator dots, validation with inline errors, success screen after submit
- Left panel shows benefits list when in registration mode
- «Зарегистрировать отель» / «Войти» toggle links

UsersPage (/users):
- Staff list table: avatar with custom color, name, role badge, position, contacts, last login, active status
- Roles: hotel_manager, receptionist, housekeeper, accountant, security — each with label+color
- Stats cards by role (clickable to filter)
- Search by name/email/position + role filter buttons
- UserModal: avatar color picker, name/email/phone, role selector (6 roles), position field with quick-pick suggestions per role, password field, active toggle
- Delete confirmation dialog
- Sidebar: «Сотрудники» link added to Управление section

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

src/App.tsx

@@ -25,6 +25,7 @@ import { RoomServicePage } from './pages/RoomServicePage'
 import { RentalPage } from './pages/RentalPage'
 import { RoomCategoriesPage } from './pages/RoomCategoriesPage'
 import { DocumentsPage } from './pages/DocumentsPage'
+import { UsersPage } from './pages/UsersPage'
 
 export default function App() {
   return (
@@ -59,6 +60,7 @@ export default function App() {
                 <Route path="/rental"           element={<RentalPage />} />
                 <Route path="/room-categories" element={<RoomCategoriesPage />} />
                 <Route path="/documents"       element={<DocumentsPage />} />
+                <Route path="/users"           element={<UsersPage />} />
               </Route>
 
               {/* Admin routes */}