`src/engine/bare.rs` — the `BareLoop` driver

The hands: the run loop, the three handlers, finalize, and the loop’s own state. (~1,600 lines; a facade over its submodules since the big split.)

Key items

Constructors: new (empty bundle), new_with_managers (seeds a default ContextManager if none), from_machine/into_machine (checkpoint/resume).
The Loop impl: run (the match loop), finalize (commit/discard, memory consolidation, stale-stop cleanup, run-end events, cancel re-arm), should_continue, state, cancel, stop_reason.
The three handlers: handle_call_llm (transients → deferral check → do_turn → detection → feed), handle_call_tools (preresolved slots + dispatch → one results message), handle_compact (thin, delegates to bare/compact.rs).
set_error_state — Cancelled routes through machine.cancel(), everything else through machine.fail().
Internals: machine_policy(), count_context, overhead_tokens (OnceLock-cached), MAX_RECOVERY_ATTEMPTS = 5, detection_disabled (sticky, set on detection poison).
Accessors: conversation, session, run_config, tools, machine, cancel_signal, is_cancelled, turn_mode.

Behavior notes

The deferral dance: a turn whose fuller payload (with transients) crosses the compaction line defers silently — no turn events — and reserves deferred_transient_tokens so the retried turn fits.
into_machine/drop removes the managed session temp dir (best-effort).
The Done arm matches every outcome variant explicitly — future variants force a compile error here.