feat(inventory): add mandatory per-section date pickers, prevent future dates, sync transfer dates, and sort by transaction_date

backend/app/routers/inventory.py

@@ -217,6 +217,7 @@ def transaction_to_dict(tx: InventoryTransaction, wh: Warehouse | None = None) -
         "performed_by": tx.performed_by,
         "delivered_to": tx.delivered_to,
         "transaction_date": to_iso(tx.transaction_date),
+        "created_at": to_iso(tx.created_at) if hasattr(tx, "created_at") and tx.created_at else None,
         "note": tx.note,
     }
 
@@ -461,7 +462,10 @@ async def list_transactions(
             InventoryTransaction.transaction_date
             < datetime.fromisoformat(date_to).replace(tzinfo=timezone.utc) + timedelta(days=1)
         )
-    stmt = sort_query(stmt, InventoryTransaction, sort, default="-transaction_date")
+    if not sort or sort == "-transaction_date":
+        stmt = stmt.order_by(InventoryTransaction.transaction_date.desc(), InventoryTransaction.created_at.desc())
+    else:
+        stmt = sort_query(stmt, InventoryTransaction, sort, default="-transaction_date")
     items, meta = await paginate(stmt, page, page_size, db)
 
     # Enrich: warehouse name + material/brand/specs/unit for the UI rows.