feat: bootstrap from Fabric monorepo

src/messaging/dto.create-message.dto.ts

@@ -0,0 +1,59 @@
+import {
+  ArrayMaxSize,
+  IsArray,
+  IsOptional,
+  IsString,
+  MaxLength,
+  ValidateNested,
+} from 'class-validator';
+import { Type } from 'class-transformer';
+
+class AttachmentDto {
+  @IsString()
+  @MaxLength(2048)
+  url!: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(255)
+  name?: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(100)
+  mimeType?: string;
+}
+
+export class CreateMessageDto {
+  @IsString()
+  @MaxLength(4000)
+  content!: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(80)
+  clientMessageId?: string;
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(80)
+  replyToMessageId?: string;
+
+  @IsOptional()
+  @IsArray()
+  @ArrayMaxSize(50)
+  @IsString({ each: true })
+  mentions?: string[];
+
+  @IsOptional()
+  @IsArray()
+  @ArrayMaxSize(10)
+  @ValidateNested({ each: true })
+  @Type(() => AttachmentDto)
+  attachments?: AttachmentDto[];
+
+  @IsOptional()
+  @IsString()
+  @MaxLength(64)
+  authorUserId?: string;
+}