Refactor wagon specifications to rely on wagon type; remove tare weight and max payload from wagon entity and related components

apps/edr-freight-api/src/modules/wagons/dto/create-wagon.dto.ts

@@ -1,5 +1,5 @@
 import { WagonStatus } from '@edr/types';
-import { IsString, IsUUID, IsOptional, IsInt, Min, IsNumber, IsEnum } from 'class-validator';
+import { IsString, IsUUID, IsOptional, IsInt, Min, IsEnum } from 'class-validator';
 
 export class CreateWagonDto {
   @IsString()
@@ -17,13 +17,8 @@ export class CreateWagonDto {
   @Min(1)
   sequenceNumber?: number;
 
-  @IsNumber()
-  @Min(0)
-  tareWeight!: number;
-
-  @IsNumber()
-  @Min(0)
-  maxPayloadWeight!: number;
+  // Tare weight and payload capacity are not accepted here: they belong to the
+  // wagon type and are resolved through wagonTypeId.
 
   @IsOptional()
   @IsEnum(WagonStatus)