Goal\nAdd a single local command that validates the repository before release candidate packaging.\n\n## Completion Criteria\n- Add a root-level release readiness script.\n- Wire it into package scripts as pnpm release:check.\n- Verify TypeScript, lint, build, dependency audit, source file length policy, and whitespace checks.\n- Run the command locally and record the result.\n\n## Evidence\nImplemented in the Stage 2 release readiness PR.