Test the Krad graph and CLI contracts

[keys-i]

Motivation

Protect the component ordering and observable CLI behavior while the implementation remains small.

Acceptance criteria

• Tests prove the expected four-component order.
• Invalid component metadata and missing dependency behavior are covered.
• JSON plan output is parsed and checked.
• A missing source root produces exit status 1 and identifies the first missing component.
• npm test passes on the supported Node runtime.