feat(sync): add order_total field to SQLite tracking

Parse order total from GoMag JSON, store in SQLite orders table,
and expose via sync run API. Enables total display in mobile flat rows.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

api/app/routers/sync.py

@@ -149,6 +149,7 @@ async def sync_run_log(run_id: str):
                 "id_partener": o.get("id_partener"),
                 "error_message": o.get("error_message"),
                 "missing_skus": o.get("missing_skus"),
+                "order_total": o.get("order_total"),
                 "factura_numar": o.get("factura_numar"),
                 "factura_serie": o.get("factura_serie"),
             }