MessageDto
constructor(id: String = "", conversationId: String = "", seq: Int = 0, senderType: SenderType = SenderType.SYSTEM, content: String = "", createdAt: Instant = Instant.EPOCH, senderId: String? = null, senderName: String? = null, visibility: String = "public", contentType: String = "text", attachments: List<Attachment> = emptyList(), clientId: String? = null, metadata: JsonObject? = null, deliveryStatus: String? = null, deliveryError: String? = null, readAt: Instant? = null)