Adds a "Configuration env vars" section listing every RELICARIO_*
variable read by production code, with purpose and trust boundary.
Splits user-facing vars from debug-only ones (cfg(debug_assertions))
to make the attack surface explicit for security reviewers.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Clarifies what AEAD protects (tampering) vs. what it doesn't (deletion,
rollback). Documents that git history is the audit trail and device
authentication is the mitigation.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>