Wire `pre_turn_snapshot` and `post_turn_snapshot` helpers into
`core::turn`, then call them from `Engine::handle_send_message` —
pre-turn fires right after `turn_counter` is incremented, post-turn
fires right after `Event::TurnComplete` is emitted.
Both hooks are dispatched via `tokio::task::spawn_blocking` so the
agent loop never waits on the side-git commit, and helper failures are
swallowed at WARN log level so a busted disk or missing `git` binary
can never derail a turn (per the snapshot module's documented
non-fatal contract).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Hunter Bown
8ff4f66b95