refactor(workspace): restore yaml exports and align docker builds

- return scenario export payloads as yaml to match existing workflows

- harden step reordering flow for drag-and-drop and one-based ui labels

- switch server container to workspace-lockfile installs and root ignore rules

server/src/scenario/dto/scenario-export.dto.ts

@@ -3,21 +3,14 @@ import { Type } from "class-transformer";
 import {
   IsArray,
   IsIn,
-  IsInt,
   IsNotEmpty,
   IsOptional,
   IsString,
   IsUUID,
-  Min,
   ValidateNested,
 } from "class-validator";
 
 export class ScenarioStepExportDto {
-  @ApiProperty()
-  @IsInt()
-  @Min(0)
-  order: number;
-
   @ApiPropertyOptional()
   @IsOptional()
   @IsString()