docs: root ERD.md (SQLite ERD, Mermaid), merge docs/do-erd.md

README.md

@@ -101,7 +101,7 @@ Office (`:5721`) switches mode / model mode / require_plate (403 on operator
 POST). **DO manual flow:** open `http://<jetson>:5000/operator` on a phone →
 Ambil Foto DO → review/edit OCR fields → Mulai Batch → count → Selesai
 (soft-warn if zone busy). Discard only when both sack and box nets are 0.
-ERD: [`docs/do-erd.md`](docs/do-erd.md).
+ERD: [`ERD.md`](ERD.md).
 
 ## Repository layout
 
@@ -131,7 +131,7 @@ Script-by-script reference: [`docs/scripts.md`](docs/scripts.md).
 - [`docs/models.md`](docs/models.md) — model inventory & detection-mode support matrix
 - [`docs/configuration.md`](docs/configuration.md) — all config files/variables
 - [`docs/deployment.md`](docs/deployment.md) — Jetson services, TensorRT, deploy flow
-- [`docs/do-erd.md`](docs/do-erd.md) — delivery-order / batch ERD (Mermaid)
+- [`ERD.md`](ERD.md) — SQLite ERD (Mermaid): batches / delivery_orders / daily_summaries
 - [`docs/operator-tiles-history-plan.md`](docs/operator-tiles-history-plan.md) — operator tiles + history cleanup plan
 - [`docs/scripts.md`](docs/scripts.md) — entry points & utility scripts
 - [`CHANGELOG.md`](CHANGELOG.md) — release history