Add bounded agent routing packets

[iperev]

Summary

• make the default agent-route envelope a bounded, token-efficient brief packet with explicit full-detail replay
• close CLI/spec/binding/version-edge authority and installed-carrier proof for the new wire contract
• update repository-owned toolchains, dependencies, and GitHub Actions to the verified stable baseline for 2026-09-02
• admit npm 12 wire forms, macOS 13 release compatibility, and whole-process snapshot cleanup

Validation

• npx --yes npm@12.0.2 run check
• targeted normal and race tests for agent-route and repository snapshot cleanup
• adversarial mutation review of byte bounds, omission accounting, lazy blocker materialization, release linkage, package closure, and process-group termination
• predecessor v0.5.1 published and verified in npm, PyPI, and GitHub Releases

Non-claims

This PR does not prove downstream consumer adoption, rollout, deployment, or production readiness.