Add docs/rules-conformance.md documenting how the repo conforms to the
vendored canon, the documentation.md vs dependency-free conflict and its
scoped resolution, the domain-mismatched rules that do not apply, and the
conscious deviations. Add docs/package-import-contract-status.md. State
the round-trip law (Lambda1/Lambda2) in DESIGN.md.
Add internal parsing events with marks, scalar styles, collection styles, alias events, and anchor/tag metadata. Add golden parser event tests for current block parser behavior.
Closes#2
