feat(server): extend GET /box/info with mixed items and attachment summary

Co-Authored-By: Claude <noreply@anthropic.com>

tests/test_attachment_boxing.py

@@ -226,3 +226,33 @@ def test_attachment_box_delete_cleans_empty_box(client: TestClient, db: Session)
         },
     )
     assert recreated.status_code == 200
+
+
+def test_box_info_includes_attachment_summary(client: TestClient, db: Session):
+    cert_id, extra_id = _seed(db)
+    client.put(
+        "/CargoTrace/attachment/config",
+        json={
+            "zongpai_no": "26BW0011",
+            "determination": "has",
+            "items": [
+                {"category_id": cert_id, "expected_qty": 80},
+                {"category_id": extra_id, "expected_qty": 5},
+            ],
+        },
+    )
+    client.post(
+        "/CargoTrace/attachment/box",
+        json={
+            "zongpai_no": "26BW0011",
+            "category_id": cert_id,
+            "box_no": 951,
+            "quantity": 80,
+        },
+    )
+    info = client.get(
+        "/CargoTrace/box/info", params={"zongpai_no": "26BW0011"}
+    ).json()
+    assert info["attachment_summary"]["determination"] == "has"
+    assert info["attachment_summary"]["all_complete"] is False
+    assert info["attachment_summary"]["pending_count"] == 1  # extra not yet boxed