Adds an asyncio-based background scheduler that polls the Gainwell
MFT inbound path, downloads new files, and routes them through the
appropriate parser (999 / 835 / 277CA / TA1). Idempotent (re-ticks
and restarts skip already-processed files via the new
processed_inbound_files table). Crash-safe (per-file try/except so
one bad file doesn't stop the loop).
Lifespan auto-configures from the seeded dzinesco clearhouse's SFTP
block; auto-start is opt-in via CYCLONE_SCHEDULER_AUTOSTART.
Five admin endpoints added:
GET /api/admin/scheduler/status
POST /api/admin/scheduler/start
POST /api/admin/scheduler/stop
POST /api/admin/scheduler/tick
GET /api/admin/scheduler/processed-files?status=&limit=
20 new tests (15 unit + 5 API).