Rs bootstrap plan validation

This documentation delivery is based on 01d82825d93129401df064ff3e0c3adae04d852a. The exact changed-document identities, command, source revision, path/link checks and all-open gate check are in validation.json.

The coordinated validator and independent architecture review are retained in soft3's planning audit. Review corrected the distinction between B and L, an independent compiler pair and interpreted execution, root availability and final Eidos delivery, and the README's unqualified compatibility claim. Final readback passed.

The pre-existing README link to reference/step.md remains unresolved and is recorded separately; this delivery introduces no unresolved local link. Only documentation and audit records change. No Cargo builds/tests were run, and no compiler, compatibility, root or RS0–RS9 acceptance result is claimed.