/// Result type returned by agent graph store operations.pub type AgentGraphStoreResult<T> = Result<T, AgentGraphStoreError>;/// Error type shared by agent graph store implementations.#[derive(Debug, thiserror::Error)]pub enum AgentGraphStoreError {    /// The caller supplied invalid request data.    #[error("invalid agent graph store request: {message}")]    InvalidRequest {        /// User-facing explanation of the invalid request.        message: String,    },    /// Catch-all for implementation failures that do not fit a more specific category.    #[error("agent graph store internal error: {message}")]    Internal {        /// User-facing explanation of the implementation failure.        message: String,    },}