chore: warehouse/tree 接口加 3 阶段耗时打点日志（查库/build_tree/序列化）

inventory-backend/app/api/v1/warehouse.py

@@ -36,19 +36,33 @@ def get_tree():
     """
     获取库位树形结构
     """
+    import time
+    from flask import current_app
+    t0 = time.time()
     try:
         # 查询所有库位，按 name 升序排序
         all_locations = SysWarehouseLocation.query.order_by(SysWarehouseLocation.name.asc()).all()
+        t1 = time.time()
 
         # 构建树形结构
         tree_data = build_tree(all_locations, parent_id=None)
+        t2 = time.time()
 
-        return jsonify({
+        resp = jsonify({
             'code': 200,
             'msg': 'success',
             'data': tree_data
         })
+        t3 = time.time()
+
+        print(
+            f"[warehouse/tree 打点] 阶段1-查库={t1 - t0:.3f}s | 阶段2-build_tree+to_dict={t2 - t1:.3f}s | "
+            f"阶段3-jsonify序列化={t3 - t2:.3f}s | 总={t3 - t0:.3f}s (rows={len(all_locations)}, tree_top={len(tree_data)})",
+            flush=True
+        )
+        return resp
     except Exception as e:
+        print(f"[warehouse/tree 打点] 异常: {e}", flush=True)
         return jsonify({
             'code': 500,
             'msg': str(e),