feat(rag): close eval pipeline with live snapshots

src/main/java/com/superbiz/agent/dto/Frontmatter.java

@@ -1,5 +1,6 @@
 package com.superbiz.agent.dto;
 
+import com.fasterxml.jackson.annotation.JsonProperty;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
@@ -39,6 +40,13 @@ public class Frontmatter {
      */
     private String category;
 
+    private String source;
+
+    private String breadcrumb;
+
+    @JsonProperty("kb_scope")
+    private String kbScope;
+
     /**
      * 章节锚点（预留字段，MVP 不使用）
      * Key: 章节标题，Value: 章节 Markdown 标题