Define and enforce tywrap ↔ tywrap-ir compatibility contract

[bbopen]

Define and enforce the compatibility contract between tywrap and tywrap-ir so users get explicit expectations and explicit failures when versions drift.

Acceptance Criteria

• compatibility expectations are documented in maintainers docs and user-facing release guidance where appropriate
• mismatch behavior is explicit and friendly instead of implicit or surprising
• release guidance explains how tywrap and tywrap-ir version independently