fix: 补齐 hutool 依赖并固定 Java 8 编译，修复钉钉 token 缓存 ClassNotFound

Co-authored-by: Cursor <cursoragent@cursor.com>

pom.xml

@@ -21,6 +21,7 @@
         <java.version>1.8</java.version>
         <maven.compiler.source>1.8</maven.compiler.source>
         <maven.compiler.target>1.8</maven.compiler.target>
+        <maven.compiler.release>8</maven.compiler.release>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
@@ -67,6 +68,12 @@
             <artifactId>fastjson</artifactId>
             <version>1.2.83</version>
         </dependency>
+        <!-- mjava UtilToken / 钉钉 token 缓存依赖；未打入包会导致 NoClassDefFoundError: CacheUtil -->
+        <dependency>
+            <groupId>cn.hutool</groupId>
+            <artifactId>hutool-all</artifactId>
+            <version>5.8.25</version>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>