//! CLI command handler modules
//!
//! Organized by functionality:
//! - `io`: File I/O operations (read, write, convert)
//! - `transform`: Data transformations (sort, filter, replace, etc.)
//! - `pandas`: Pandas-style operations (head, tail, join, groupby, etc.)
//! - `advanced`: Advanced features (validate, chart, batch, etc.)
pub use AdvancedCommandHandler;
use Result;
/// Command handler trait
///
/// All command handlers must implement this trait.