#[derive(Debug, Clone)]
pub enum Signal {
    /// Emitted when the list of conversations is updated.
    ConversationsUpdated,

    /// Emitted when the list of messages for a conversation is updated.
    /// Parameters:
    /// - conversation_id: The ID of the conversation that was updated.
    MessagesUpdated(String),

    /// Emitted when an attachment has been downloaded.
    /// Parameters:
    /// - attachment_id: The ID of the attachment that was downloaded.
    AttachmentDownloaded(String),
}