Rust Semver and Release Workflow

Authority: Cargo Semver Reference, RFC 1105 (Semver), cargo-semver-checks, RustSec Advisory Database.

This skill owns what is and isn't a breaking change in Rust, the publishing workflow for crates.io, and workspace-wide release coordination. It does not own API design (rust-api-design), Cargo manifest mechanics (rust-cargo-build), or lint config (rust-style-clippy).

Capability Boundaries

✅ Strengths

1. Determining whether a specific code change is a major, minor, or patch bump
2. Understanding pre-1.0 (0.x.y) special rules
3. Running and interpreting cargo-semver-checks (270+ lints)
4. Coordinating multi-crate workspace releases via cargo-workspaces
5. Handling yank, deprecate, and RustSec advisory workflows
6. Knowing the semver implications of #[non_exhaustive], sealed traits, feature flags, hidden modules
7. Writing release notes that match the change type