Merge branch 'development'

Release-crates workflow, MCP server, and 18 development commits ready for v0.3.0. Conflict resolution: took main's version of release-mechanics files (SKILL.md v1.1, release-github.yml with concurrency groups) since they reflect the currently-published release process. The Cargo.lock auto-merge picked up the real dependency addition (tokio in mcp) and not just package-entry reordering.