//! Docs-feature observer family. Gated behind `[features.docs]`. Reads
//! Layer A (`.heal/doc_pairs.json`) + Layer B (standalone prose docs)
//! and emits the v0.3+ docs-substrate Findings.
//!
//! [`corpus`], [`walk`], and [`markdown`] are Findings-free helpers
//! shared across the observer set.
pub