//! Release gates, publish-order walker, deploy.
//!
//! Each gate is a free function returning `Result<()>`. Generated
//! release binaries call them in the order defined in
//! `workspace_holger/release/SPEC.md`.
/// `nornir release undo` (task #32): reverse a release run's mutating steps from
/// the `release_changes` ledger (un-bump, restore `[patch]`, delete/reset branch,
/// yank an immutable publish) + the record wrappers the release path drives.