fix: 补回Map import

src/main/java/com/example/building/controller/ProductController.java

@@ -11,6 +11,7 @@ import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
+import java.util.Map;
 
 /**
  * 商品控制器