//! Preprocessing steps for the execution pipeline.
//!
//! This module provides thin step wrappers that integrate core audio/image
//! processing implementations with the execution pipeline. Each step handles
//! the envelope interface and delegates to the core implementation.
//!
//! ## Architecture
//!
//! ```text
//! template_executor
//! └── preprocessing step (this module)
//! └── core implementation (audio/, image/, etc.)
//! ```
//!
//! ## Available Steps
//!
//! - `mel_spectrogram`: Audio → Mel spectrogram conversion for ASR models
pub use ;