fix(backend): 显式依赖 logback-classic 避免生产环境 NoClassDefFoundError: ThrowableProxy

cfc-backend/pom.xml

@@ -95,6 +95,12 @@
             <artifactId>spring-security-crypto</artifactId>
         </dependency>
 
+        <!-- Logback (显式依赖，避免 Tomcat 线程类加载器看不到 BOOT-INF/lib/ 导致 NoClassDefFoundError) -->
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+        </dependency>
+
         <!-- Apache Commons -->
         <dependency>
             <groupId>org.apache.commons</groupId>