Interface AdoptOptions

Add an mj:standards npm script to package.json.

Also write a CI workflow.

Declare mjUILayer on packages that already comply.

Without this, a fresh adoption produces a config that enforces nothing — every package is undeclared, so every package is skipped, and the repo gets a green check that means nothing. Declaring the already-clean packages is what makes the first run honest.

Report what would happen, change nothing.

Limit to these check ids. Empty means "every check at or below Version".

Review and enable standards newer than the repo's recorded StandardsVersion, and bump it. Without this, adopt on a configured repo leaves the version line alone — which is what makes upgrading the package safe.

The version being adopted against — normally the installed MJ/CLI version.