Adds the missing feature writeup for circuit_breaker.py (enabled by default
in PR #10 but never documented) plus the mechanism finding that eval calls
correctly bypass it: pinned dispatch has no `alternatives` to fail over to,
so routing eval through the dispatcher would add no benefit and one real
downside — eval-induced failures poisoning circuit-breaker state for
production traffic.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VRQXz5SYZYVWscxS1QqF6U
