action.yml workspace propagation

Craft workspace keys are literal relative paths or safe glob patterns, expanded to concrete directory paths relative to .craft.yml; Action titles always carry the full concrete path. Chose path-based workspace identity over legacy symbolic names because monorepos need independent release units such as packages/cli; a slash path like cli/v2 is valid concrete-path syntax, not deprecated compatibility. Reject unsafe segments, overlapping matches, files, and simultaneous Action path plus workspace; validate before craft prepare mutates state. Omit --workspace when absent to preserve legacy title identity.