refactor: 统一RAG接口查询请求与返回体

src/main/java/com/bruce/rag/service/IRagDocumentService.java

@@ -1,7 +1,12 @@
 package com.bruce.rag.service;
 
 import com.baomidou.mybatisplus.extension.service.IService;
+import com.bruce.rag.dto.request.RagDocumentQueryRequest;
 import com.bruce.rag.entity.RagDocument;
 
+import java.util.List;
+
 public interface IRagDocumentService extends IService<RagDocument> {
+
+    List<RagDocument> query(RagDocumentQueryRequest request);
 }