Merge pull request #9 from github/wbreza-simplify-command-artifacts

Simplify separate commands with automatic artifact discovery

Invoke Vally directly for native lint and evaluation runs (#6)

Provide default validate/lint/run/report Action usage, explicit commands for optional isolation, and latest or exact Vally acquisition.

Closes #5

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>