style: add UnusedImports rule

WhatDamon · WhatDamon · commit 9465a3120e7b · 2026-04-04T12:38:06.000+08:00
diff --git a/checkstyle.xml b/checkstyle.xml
@@ -66,5 +66,7 @@
         <module name="MethodName">
             <property name="format" value="^[a-z][a-zA-Z0-9_]*$"/>
         </module>
+
+        <module name="UnusedImports"/>
     </module>
 </module>
