- Split profile_handlers.go into profile_handlers_core.go, profile_handlers_management_core.go, and profile_handlers_management_delete.go
- Simplify OrderProfileHandlerWithRepo with ICCID/IMSI-only validation and "downloaded" state
- Remove webhook and message queue notifications from order handler
- Add UpdateProfileHandler with state validation for downloaded/activated/deactivated/expired
- Add DeleteProfileHandler with existence
- Add SMDPHandler struct with manager field and NewSMDPHandler constructor
- Add AddCarrier endpoint with JSON binding and carrier configuration support
- Add RemoveCarrier endpoint with carrier ID parameter validation
- Add DownloadProfile endpoint with 30-second timeout and context cancellation
- Add GetCarrierStatus endpoint returning all carriers with timestamp
- Add GetProfileStatus endpoint with EID/ICCID validation