Move the four providers onto _runtime and _shell_command; add expected_runtime_scripts and extra artifact checks to _runtime. Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq
Add _runtime (paths, config validation, status checks) and _shell_command (quoting, parsers) and move the four providers onto them. Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq