Implement buy flow and migrate DTOs to schemas

Move DTO definitions from dto/ to schemas/ and update imports.
Add buy handler with FSM state management for device selection,
whitelist toggling, and duration choice. Include pricing logic,
inline keyboards, and new configuration fields.

services/user_service.py

@@ -6,8 +6,8 @@ from remnawave import RemnawaveSDK
 from config import settings
 from db.models.tickets import TicketStatus
 from db.models.users import User
-from dto.tickets import NewTicketDTO
-from dto.users import NewUserDTO, TicketCreator
+from schemas.tickets import NewTicketDTO
+from schemas.users import NewUserDTO, TicketCreator
 from repositories import UserRepository
 from repositories.tickets import TicketRepository
 from services.rw import RWUserInfo, get_user_by_telegram_id
@@ -107,7 +107,6 @@ class UserService:
 
         if ticket:
             try:
-                print(ticket.thread_id)
                 await msg.copy_to(
                     chat_id=settings.admin_group_id, message_thread_id=ticket.thread_id
                 )