feat(BE-58,59,60,61): implement stock transfer API, validation, audit log, and schema update

- Build stock transfer API with nested details, deliveries, and items
- Extend DB schema for stock transfers
- Implement validation for transfer request and stock
- Prepare/implement transfer audit log structure
- Preload all relations for complete response
- Update DTOs for nested response
- Remove redundant root fields, use relation objects

internal/modules/inventory/transfers/validations/transfer.validation.go

@@ -25,7 +25,6 @@ type TransferDelivery struct {
 	DeliveryCostPerItem float64                   `json:"delivery_cost_per_item" validate:"required"`
 	Document            string                    `json:"document"`
 	DriverName          string                    `json:"driver_name" validate:"required"`
-	DeliveryNoteNumber  string                    `json:"delivery_note_number" validate:"required"`
 	VehiclePlate        string                    `json:"vehicle_plate" validate:"required"`
 	SupplierID          uint                      `json:"supplier_id" validate:"required"`
 	Products            []TransferDeliveryProduct `json:"products" validate:"required,dive"`