These endpoints had zero CLI callers and served only the web UI demo.
Verification and retros were `not_implemented` stubs in real mode;
sessions had an in-memory implementation but no CLI usage. Removing
them shrinks the API surface and eliminates ~9,000 lines of dead code.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>