chore: move loose helper scripts into scripts/, fix doc refs

docs/deployment.md

@@ -44,7 +44,7 @@ loads `.engine` only — see `models/modelREADME.md` for which weights each mode
   `batch_history_folder/batch_<ts>.json` + `hasil_perhitungan.json` (per-batch reports).
 - Live frame: `/dev/shm/jetson-counter/live_frame.jpg` (written every 2nd frame,
   consumed by `/api/live-video` MJPEG).
-- Helpers: `check_jetson_db.py` (root); retired ops scripts in `archive/`
+- Helpers: `scripts/check_jetson_db.py`; retired ops scripts in `archive/`
   (`backup.py`, `dump_db.py`, `migrate_jetson_db.py`, `merge_batches_*.py`,
   `update_batches.py`, `diagnose_truck_jetson.py`).