feat: Add loot builder backend + static data + DB migration

- Migration 013: loot_profiles table (JSONB loot_table + loot_groups, license-scoped)
- TypeORM entity matching migration schema exactly
- NestJS loot module: 10 endpoints (CRUD, duplicate, apply, import, export, containers)
- Multiplier logic recursively scales Min/Max/Scrap across loot tables and groups
- Apply-to-server writes BetterLoot JSON via NATS file manager + RCON reload
- Frontend static data: 191 Rust items, 51 container prefabs
- TypeScript types for BetterLoot data model (PrefabLoot, LootEntry, LootRNG, etc.)
- Fix vue-tsc errors: UngroupedItems uses LootRNG, null safety in store/view

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend-nest/src/app.module.ts

@@ -35,6 +35,7 @@ import { SetupModule } from './modules/setup/setup.module';
 import { MigrationModule } from './modules/migration/migration.module';
 import { ChangelogModule } from './modules/changelog/changelog.module';
 import { FilesModule } from './modules/files/files.module';
+import { LootModule } from './modules/loot/loot.module';
 
 // Shared Services
 import { NatsService } from './services/nats.service';
@@ -105,6 +106,7 @@ import { NatsBridgeGateway } from './gateways/nats-bridge.gateway';
     MigrationModule,
     ChangelogModule,
     FilesModule,
+    LootModule,
   ],
   providers: [
     // Global guards (order matters: auth first, then license, then permissions)

backend-nest/src/entities/loot-profile.entity.ts

@@ -0,0 +1,36 @@
+import { Entity, PrimaryGeneratedColumn, Column, ManyToOne, JoinColumn } from 'typeorm';
+import { License } from './license.entity';
+
+@Entity('loot_profiles')
+export class LootProfile {
+  @PrimaryGeneratedColumn('uuid')
+  id: string;
+
+  @Column({ type: 'uuid' })
+  license_id: string;
+
+  @Column({ type: 'varchar', length: 100 })
+  profile_name: string;
+
+  @Column({ type: 'text', nullable: true })
+  description: string | null;
+
+  @Column({ type: 'jsonb', default: () => "'{}'" })
+  loot_table: Record<string, any>;
+
+  @Column({ type: 'jsonb', default: () => "'{}'" })
+  loot_groups: Record<string, any>;
+
+  @Column({ type: 'boolean', default: false })
+  is_active: boolean;
+
+  @Column({ type: 'timestamptz', default: () => 'NOW()' })
+  created_at: Date;
+
+  @Column({ type: 'timestamptz', default: () => 'NOW()' })
+  updated_at: Date;
+
+  @ManyToOne(() => License, { onDelete: 'CASCADE' })
+  @JoinColumn({ name: 'license_id' })
+  license: License;
+}

backend-nest/src/modules/loot/data/rust-containers.ts

@@ -0,0 +1,39 @@
+export interface RustContainerInfo {
+  prefab: string;
+  name: string;
+  category: string;
+}
+
+export const RUST_CONTAINERS: RustContainerInfo[] = [
+  // Crates
+  { prefab: 'assets/bundled/prefabs/radtown/crate_normal.prefab', name: 'Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_normal_2.prefab', name: 'Crate (Small)', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_elite.prefab', name: 'Elite Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_tools.prefab', name: 'Tool Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_food_1.prefab', name: 'Food Crate (Small)', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_food_2.prefab', name: 'Food Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_medical.prefab', name: 'Medical Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_mine.prefab', name: 'Mine Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_basic.prefab', name: 'Basic Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_underwater_basic.prefab', name: 'Underwater Basic Crate', category: 'crates' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_underwater_advanced.prefab', name: 'Underwater Advanced Crate', category: 'crates' },
+  // Barrels
+  { prefab: 'assets/bundled/prefabs/radtown/loot_barrel_1.prefab', name: 'Barrel', category: 'barrels' },
+  { prefab: 'assets/bundled/prefabs/radtown/loot_barrel_2.prefab', name: 'Barrel 2', category: 'barrels' },
+  { prefab: 'assets/bundled/prefabs/radtown/oil_barrel.prefab', name: 'Oil Barrel', category: 'barrels' },
+  // Military
+  { prefab: 'assets/bundled/prefabs/radtown/crate_helicopter.prefab', name: 'Helicopter Crate', category: 'military' },
+  { prefab: 'assets/bundled/prefabs/radtown/bradley_crate.prefab', name: 'Bradley Crate', category: 'military' },
+  { prefab: 'assets/bundled/prefabs/radtown/supply_drop.prefab', name: 'Supply Drop', category: 'military' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_locked.prefab', name: 'Locked Crate', category: 'military' },
+  { prefab: 'assets/bundled/prefabs/radtown/crate_hackable.prefab', name: 'Hackable Crate', category: 'military' },
+  // NPCs
+  { prefab: 'assets/rust.ai/agents/npcplayer/humannpc/scientist/scientistnpc_full_any.prefab', name: 'Scientist', category: 'npcs' },
+  { prefab: 'assets/rust.ai/agents/npcplayer/humannpc/scientist/scientistnpc_heavy.prefab', name: 'Heavy Scientist', category: 'npcs' },
+  { prefab: 'assets/rust.ai/agents/npcplayer/humannpc/scientist/scientistnpc_oilrig.prefab', name: 'Oil Rig Scientist', category: 'npcs' },
+  { prefab: 'assets/rust.ai/agents/npcplayer/humannpc/scientist/scientistnpc_cargo.prefab', name: 'Cargo Ship Scientist', category: 'npcs' },
+  { prefab: 'assets/rust.ai/agents/npcplayer/humannpc/tunneldweller/npc_tunneldweller.prefab', name: 'Tunnel Dweller', category: 'npcs' },
+  // Other
+  { prefab: 'assets/bundled/prefabs/radtown/minecart.prefab', name: 'Minecart', category: 'other' },
+  { prefab: 'assets/bundled/prefabs/radtown/vehicle_parts.prefab', name: 'Vehicle Parts', category: 'other' },
+];

backend-nest/src/modules/loot/dto/apply-loot-profile.dto.ts

@@ -0,0 +1,9 @@
+import { IsNumber, IsIn } from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+
+export class ApplyLootProfileDto {
+  @ApiProperty({ example: 1, description: 'Loot multiplier', enum: [1, 2, 5, 10] })
+  @IsNumber()
+  @IsIn([1, 2, 5, 10])
+  multiplier: number;
+}

backend-nest/src/modules/loot/dto/create-loot-profile.dto.ts

@@ -0,0 +1,24 @@
+import { IsString, IsOptional, IsObject, MaxLength } from 'class-validator';
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
+
+export class CreateLootProfileDto {
+  @ApiProperty({ example: 'Vanilla 2x' })
+  @IsString()
+  @MaxLength(100)
+  profile_name: string;
+
+  @ApiPropertyOptional({ example: 'Standard 2x loot table' })
+  @IsString()
+  @IsOptional()
+  description?: string;
+
+  @ApiPropertyOptional()
+  @IsObject()
+  @IsOptional()
+  loot_table?: Record<string, any>;
+
+  @ApiPropertyOptional()
+  @IsObject()
+  @IsOptional()
+  loot_groups?: Record<string, any>;
+}

backend-nest/src/modules/loot/dto/import-loot-profile.dto.ts

@@ -0,0 +1,23 @@
+import { IsString, IsObject, IsOptional, MaxLength } from 'class-validator';
+import { ApiProperty, ApiPropertyOptional } from '@nestjs/swagger';
+
+export class ImportLootProfileDto {
+  @ApiProperty({ example: 'Imported from Looty' })
+  @IsString()
+  @MaxLength(100)
+  profile_name: string;
+
+  @ApiPropertyOptional()
+  @IsString()
+  @IsOptional()
+  description?: string;
+
+  @ApiProperty({ description: 'BetterLoot LootTables.json content' })
+  @IsObject()
+  loot_table: Record<string, any>;
+
+  @ApiPropertyOptional({ description: 'BetterLoot LootGroups.json content' })
+  @IsObject()
+  @IsOptional()
+  loot_groups?: Record<string, any>;
+}

backend-nest/src/modules/loot/dto/update-loot-profile.dto.ts

@@ -0,0 +1,30 @@
+import { IsString, IsOptional, IsObject, IsBoolean, MaxLength } from 'class-validator';
+import { ApiPropertyOptional } from '@nestjs/swagger';
+
+export class UpdateLootProfileDto {
+  @ApiPropertyOptional()
+  @IsString()
+  @MaxLength(100)
+  @IsOptional()
+  profile_name?: string;
+
+  @ApiPropertyOptional()
+  @IsString()
+  @IsOptional()
+  description?: string;
+
+  @ApiPropertyOptional()
+  @IsObject()
+  @IsOptional()
+  loot_table?: Record<string, any>;
+
+  @ApiPropertyOptional()
+  @IsObject()
+  @IsOptional()
+  loot_groups?: Record<string, any>;
+
+  @ApiPropertyOptional()
+  @IsBoolean()
+  @IsOptional()
+  is_active?: boolean;
+}

backend-nest/src/modules/loot/loot.controller.ts

@@ -0,0 +1,112 @@
+import {
+  Controller,
+  Get,
+  Post,
+  Put,
+  Delete,
+  Body,
+  Param,
+  Query,
+  UseGuards,
+} from '@nestjs/common';
+import { ApiTags, ApiBearerAuth, ApiOperation, ApiQuery } from '@nestjs/swagger';
+import { LootService } from './loot.service';
+import { CreateLootProfileDto } from './dto/create-loot-profile.dto';
+import { UpdateLootProfileDto } from './dto/update-loot-profile.dto';
+import { ApplyLootProfileDto } from './dto/apply-loot-profile.dto';
+import { ImportLootProfileDto } from './dto/import-loot-profile.dto';
+import { CurrentTenant } from '../../common/decorators/current-tenant.decorator';
+import { RequirePermission } from '../../common/decorators/require-permission.decorator';
+import { JwtAuthGuard } from '../../common/guards/jwt-auth.guard';
+import { PermissionsGuard } from '../../common/guards/permissions.guard';
+
+@ApiTags('loot')
+@ApiBearerAuth()
+@Controller('loot')
+@UseGuards(JwtAuthGuard, PermissionsGuard)
+export class LootController {
+  constructor(private readonly lootService: LootService) {}
+
+  @Get('profiles')
+  @RequirePermission('loot.view')
+  @ApiOperation({ summary: 'List loot profiles (summaries)' })
+  getProfiles(@CurrentTenant() licenseId: string) {
+    return this.lootService.getProfiles(licenseId);
+  }
+
+  @Get('profiles/:id')
+  @RequirePermission('loot.view')
+  @ApiOperation({ summary: 'Get full loot profile with data' })
+  getProfile(@CurrentTenant() licenseId: string, @Param('id') id: string) {
+    return this.lootService.getProfile(licenseId, id);
+  }
+
+  @Post('profiles')
+  @RequirePermission('loot.manage')
+  @ApiOperation({ summary: 'Create loot profile' })
+  createProfile(@CurrentTenant() licenseId: string, @Body() dto: CreateLootProfileDto) {
+    return this.lootService.createProfile(licenseId, dto);
+  }
+
+  @Put('profiles/:id')
+  @RequirePermission('loot.manage')
+  @ApiOperation({ summary: 'Update loot profile' })
+  updateProfile(
+    @CurrentTenant() licenseId: string,
+    @Param('id') id: string,
+    @Body() dto: UpdateLootProfileDto,
+  ) {
+    return this.lootService.updateProfile(licenseId, id, dto);
+  }
+
+  @Delete('profiles/:id')
+  @RequirePermission('loot.manage')
+  @ApiOperation({ summary: 'Delete loot profile' })
+  deleteProfile(@CurrentTenant() licenseId: string, @Param('id') id: string) {
+    return this.lootService.deleteProfile(licenseId, id);
+  }
+
+  @Post('profiles/:id/duplicate')
+  @RequirePermission('loot.manage')
+  @ApiOperation({ summary: 'Duplicate loot profile' })
+  duplicateProfile(@CurrentTenant() licenseId: string, @Param('id') id: string) {
+    return this.lootService.duplicateProfile(licenseId, id);
+  }
+
+  @Post('profiles/:id/apply')
+  @RequirePermission('loot.manage')
+  @ApiOperation({ summary: 'Apply loot profile to server with multiplier' })
+  applyToServer(
+    @CurrentTenant() licenseId: string,
+    @Param('id') id: string,
+    @Body() dto: ApplyLootProfileDto,
+  ) {
+    return this.lootService.applyToServer(licenseId, id, dto.multiplier);
+  }
+
+  @Post('import')
+  @RequirePermission('loot.manage')
+  @ApiOperation({ summary: 'Import BetterLoot/Looty JSON as new profile' })
+  importProfile(@CurrentTenant() licenseId: string, @Body() dto: ImportLootProfileDto) {
+    return this.lootService.importProfile(licenseId, dto);
+  }
+
+  @Get('export/:id')
+  @RequirePermission('loot.view')
+  @ApiOperation({ summary: 'Export loot profile as BetterLoot JSON' })
+  @ApiQuery({ name: 'multiplier', required: false, example: 1 })
+  exportProfile(
+    @CurrentTenant() licenseId: string,
+    @Param('id') id: string,
+    @Query('multiplier') multiplier: string,
+  ) {
+    return this.lootService.exportProfile(licenseId, id, multiplier ? parseInt(multiplier, 10) : 1);
+  }
+
+  @Get('containers')
+  @RequirePermission('loot.view')
+  @ApiOperation({ summary: 'Get list of Rust container prefabs' })
+  getContainers() {
+    return this.lootService.getContainers();
+  }
+}

backend-nest/src/modules/loot/loot.module.ts

@@ -0,0 +1,14 @@
+import { Module } from '@nestjs/common';
+import { TypeOrmModule } from '@nestjs/typeorm';
+import { LootController } from './loot.controller';
+import { LootService } from './loot.service';
+import { LootProfile } from '../../entities/loot-profile.entity';
+import { NatsService } from '../../services/nats.service';
+
+@Module({
+  imports: [TypeOrmModule.forFeature([LootProfile])],
+  controllers: [LootController],
+  providers: [LootService, NatsService],
+  exports: [LootService],
+})
+export class LootModule {}

backend-nest/src/modules/loot/loot.service.ts

@@ -0,0 +1,258 @@
+import { Injectable, Logger, NotFoundException, HttpException, HttpStatus } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Repository } from 'typeorm';
+import { LootProfile } from '../../entities/loot-profile.entity';
+import { NatsService } from '../../services/nats.service';
+import { CreateLootProfileDto } from './dto/create-loot-profile.dto';
+import { UpdateLootProfileDto } from './dto/update-loot-profile.dto';
+import { ImportLootProfileDto } from './dto/import-loot-profile.dto';
+import { RUST_CONTAINERS } from './data/rust-containers';
+
+@Injectable()
+export class LootService {
+  private readonly logger = new Logger(LootService.name);
+
+  constructor(
+    @InjectRepository(LootProfile)
+    private readonly lootRepo: Repository<LootProfile>,
+    private readonly natsService: NatsService,
+  ) {}
+
+  /** List profiles for a license (summaries — no JSONB) */
+  async getProfiles(licenseId: string) {
+    const profiles = await this.lootRepo.find({
+      where: { license_id: licenseId },
+      select: ['id', 'profile_name', 'description', 'is_active', 'created_at', 'updated_at'],
+      order: { created_at: 'DESC' },
+    });
+    return { profiles };
+  }
+
+  /** Get full profile with JSONB data */
+  async getProfile(licenseId: string, profileId: string) {
+    const profile = await this.lootRepo.findOne({
+      where: { id: profileId, license_id: licenseId },
+    });
+    if (!profile) throw new NotFoundException('Loot profile not found');
+    return { profile };
+  }
+
+  /** Create a new profile */
+  async createProfile(licenseId: string, dto: CreateLootProfileDto) {
+    const profile = this.lootRepo.create({
+      license_id: licenseId,
+      profile_name: dto.profile_name,
+      description: dto.description || null,
+      loot_table: dto.loot_table || {},
+      loot_groups: dto.loot_groups || {},
+    });
+    const saved = await this.lootRepo.save(profile);
+    return { profile: saved };
+  }
+
+  /** Update an existing profile */
+  async updateProfile(licenseId: string, profileId: string, dto: UpdateLootProfileDto) {
+    const profile = await this.lootRepo.findOne({
+      where: { id: profileId, license_id: licenseId },
+    });
+    if (!profile) throw new NotFoundException('Loot profile not found');
+
+    if (dto.profile_name !== undefined) profile.profile_name = dto.profile_name;
+    if (dto.description !== undefined) profile.description = dto.description;
+    if (dto.loot_table !== undefined) profile.loot_table = dto.loot_table;
+    if (dto.loot_groups !== undefined) profile.loot_groups = dto.loot_groups;
+    if (dto.is_active !== undefined) profile.is_active = dto.is_active;
+    profile.updated_at = new Date();
+
+    const saved = await this.lootRepo.save(profile);
+    return { profile: saved };
+  }
+
+  /** Delete a profile */
+  async deleteProfile(licenseId: string, profileId: string) {
+    const result = await this.lootRepo.delete({ id: profileId, license_id: licenseId });
+    if (result.affected === 0) throw new NotFoundException('Loot profile not found');
+    return { deleted: true };
+  }
+
+  /** Duplicate a profile */
+  async duplicateProfile(licenseId: string, profileId: string) {
+    const source = await this.lootRepo.findOne({
+      where: { id: profileId, license_id: licenseId },
+    });
+    if (!source) throw new NotFoundException('Loot profile not found');
+
+    const copy = this.lootRepo.create({
+      license_id: licenseId,
+      profile_name: `${source.profile_name} (Copy)`,
+      description: source.description,
+      loot_table: JSON.parse(JSON.stringify(source.loot_table)),
+      loot_groups: JSON.parse(JSON.stringify(source.loot_groups)),
+      is_active: false,
+    });
+    const saved = await this.lootRepo.save(copy);
+    return { profile: saved };
+  }
+
+  /** Apply profile to server with multiplier */
+  async applyToServer(licenseId: string, profileId: string, multiplier: number) {
+    const profile = await this.lootRepo.findOne({
+      where: { id: profileId, license_id: licenseId },
+    });
+    if (!profile) throw new NotFoundException('Loot profile not found');
+
+    // Deep clone and apply multiplier
+    const scaledTable = JSON.parse(JSON.stringify(profile.loot_table));
+    const scaledGroups = JSON.parse(JSON.stringify(profile.loot_groups));
+
+    if (multiplier !== 1) {
+      this.applyMultiplierToTable(scaledTable, multiplier);
+      this.applyMultiplierToGroups(scaledGroups, multiplier);
+    }
+
+    const lootTablesJson = JSON.stringify(scaledTable, null, 2);
+    const lootGroupsJson = JSON.stringify(scaledGroups, null, 2);
+
+    try {
+      // Write LootTables.json via file manager NATS
+      await this.natsService.request(
+        `corrosion.${licenseId}.files.cmd`,
+        {
+          func: 'fm_save',
+          path: 'server://oxide/data/BetterLoot/LootTables.json',
+          content: lootTablesJson,
+        },
+        30000,
+      );
+
+      // Write LootGroups.json via file manager NATS
+      await this.natsService.request(
+        `corrosion.${licenseId}.files.cmd`,
+        {
+          func: 'fm_save',
+          path: 'server://oxide/data/BetterLoot/LootGroups.json',
+          content: lootGroupsJson,
+        },
+        30000,
+      );
+
+      // Reload BetterLoot plugin via RCON
+      await this.natsService.publish(
+        `corrosion.${licenseId}.cmd.server`,
+        {
+          action: 'command',
+          command: 'oxide.reload BetterLoot',
+          timestamp: new Date().toISOString(),
+        },
+      );
+
+      // Mark this profile as active, deactivate others
+      await this.lootRepo.update({ license_id: licenseId }, { is_active: false });
+      await this.lootRepo.update(
+        { id: profileId, license_id: licenseId },
+        { is_active: true, updated_at: new Date() },
+      );
+
+      return {
+        success: true,
+        message: `Profile "${profile.profile_name}" applied with ${multiplier}x multiplier`,
+        profile_name: profile.profile_name,
+        multiplier,
+      };
+    } catch (error) {
+      this.logger.error(`Failed to apply loot profile: ${(error as Error).message}`);
+      throw new HttpException(
+        'Failed to apply loot profile — agent may be offline',
+        HttpStatus.SERVICE_UNAVAILABLE,
+      );
+    }
+  }
+
+  /** Import BetterLoot/Looty JSON as a new profile */
+  async importProfile(licenseId: string, dto: ImportLootProfileDto) {
+    const profile = this.lootRepo.create({
+      license_id: licenseId,
+      profile_name: dto.profile_name,
+      description: dto.description || 'Imported profile',
+      loot_table: dto.loot_table,
+      loot_groups: dto.loot_groups || {},
+    });
+    const saved = await this.lootRepo.save(profile);
+    return { profile: saved };
+  }
+
+  /** Export profile as BetterLoot-compatible JSON with optional multiplier */
+  async exportProfile(licenseId: string, profileId: string, multiplier: number) {
+    const profile = await this.lootRepo.findOne({
+      where: { id: profileId, license_id: licenseId },
+    });
+    if (!profile) throw new NotFoundException('Loot profile not found');
+
+    const exportTable = JSON.parse(JSON.stringify(profile.loot_table));
+    const exportGroups = JSON.parse(JSON.stringify(profile.loot_groups));
+
+    if (multiplier && multiplier !== 1) {
+      this.applyMultiplierToTable(exportTable, multiplier);
+      this.applyMultiplierToGroups(exportGroups, multiplier);
+    }
+
+    return {
+      profile_name: profile.profile_name,
+      multiplier: multiplier || 1,
+      loot_table: exportTable,
+      loot_groups: exportGroups,
+    };
+  }
+
+  /** Get static list of Rust container prefabs */
+  getContainers() {
+    return { containers: RUST_CONTAINERS };
+  }
+
+  // --- Multiplier helpers ---
+
+  private applyMultiplierToTable(table: Record<string, any>, multiplier: number) {
+    for (const prefab of Object.values(table)) {
+      if (prefab?.ItemSettings) {
+        this.scaleField(prefab.ItemSettings, 'ItemsMin', multiplier);
+        this.scaleField(prefab.ItemSettings, 'ItemsMax', multiplier);
+        this.scaleField(prefab.ItemSettings, 'MinScrap', multiplier);
+        this.scaleField(prefab.ItemSettings, 'MaxScrap', multiplier);
+      }
+      if (prefab?.GuaranteedItems) {
+        this.scaleItems(prefab.GuaranteedItems, multiplier);
+      }
+      if (prefab?.UngroupedItems) {
+        this.scaleItems(prefab.UngroupedItems, multiplier);
+      }
+    }
+  }
+
+  private applyMultiplierToGroups(groups: Record<string, any>, multiplier: number) {
+    for (const group of Object.values(groups)) {
+      if (group?.GuaranteedItems) {
+        this.scaleItems(group.GuaranteedItems, multiplier);
+      }
+      if (group?.ItemList) {
+        this.scaleItems(group.ItemList, multiplier);
+      }
+    }
+  }
+
+  private scaleItems(items: Record<string, any>, multiplier: number) {
+    for (const item of Object.values(items)) {
+      this.scaleField(item, 'Min', multiplier);
+      this.scaleField(item, 'Max', multiplier);
+      // Recursively scale bonus items
+      if (item?.BonusItems) {
+        this.scaleItems(item.BonusItems, multiplier);
+      }
+    }
+  }
+
+  private scaleField(obj: Record<string, any>, field: string, multiplier: number) {
+    if (typeof obj[field] === 'number') {
+      obj[field] = Math.round(obj[field] * multiplier);
+    }
+  }
+}