docs: bound mutual Compose advisory

[Joncallim]

Summary

Documents the mutual Compose-declaration advisory added by the #240–#242 stack.

• States its exact reciprocal fresh-Docker-evidence predicate and matching observation requirement.
• Records advisory-only, deterministic, cached read-only behavior and mock/fail-closed suppression.
• States nonclaims for Compose acceptance, requiredness, start order, readiness, health, traffic, deployment failure, causality, reachability, and compromise.

Verification

• git diff --check

No issue is closed by this documentation-only PR.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-02T17:09:59.877588Z	d76ce51	PR opened

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