refactor: flatten infrastructure packages

src/main/java/com/label/annotation/OperationLog.java

@@ -0,0 +1,18 @@
+package com.label.annotation;
+
+import java.lang.annotation.*;
+
+/**
+ * Marks a method for audit logging.
+ * The AuditAspect intercepts this annotation and writes to sys_operation_log.
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface OperationLog {
+    /** Operation type, e.g., "EXTRACTION_APPROVE", "USER_LOGIN", "TASK_CLAIM" */
+    String type();
+
+    /** Target entity type, e.g., "annotation_task", "sys_user" */
+    String targetType() default "";
+}