Turn the loose queue/audit functions in orchestrator/supervisor/queue.py into
methods on a concrete Supervisor service. The Orchestrator now owns an
injectable `self._supervisor` and calls `self._supervisor.write_proposal(...)`
etc., instead of module-level free functions — the supervise dependency is
explicit and mockable, and a Supervisor can be scoped to a `db_path` (defaults
to the host DB) so tests can point it at a temp database.
- Supervisor (in the package __init__) drops the ABC and gains write_proposal,
read_proposal, list_pending_proposals, list_all_pending_proposals,
write_response, read_response, archive_all_proposals, write_audit_entry,
read_audit_entries, plus the launch-time prepare().
- render_diff / sha256_hex are pure and stateless, so they move to
orchestrator/supervisor/util.py (re-exported from the facade) rather than
becoming methods.
- queue.py is deleted; service.py + the supervise tests call through a
Supervisor instance.
Full unit suite green (2243).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
