refactor(rag): 重构RAG查询命令处理器类名和代码格式

- 将RAGQueryCommandHandler重命名为RagQueryCommandHandler
- 调整代码缩进格式
- 优化空行布局以提高代码可读性

src/modules/rag/Application/RagQA/Handlers/RagQueryCommandHandler.cs

@@ -12,7 +12,7 @@ namespace BuildFlow.Application.RagQA.Handlers;
 /// <summary>
 /// RAG检索问答查询Command处理器（基于 MAF ChatMessage）。
 /// </summary>
-public class RAGQueryCommandHandler(
+public class RagQueryCommandHandler(
     RagDbContext db,
     IRagRetrievalService retrievalService,
     IAIChatAgent chatAgent)
@@ -21,7 +21,7 @@ public class RAGQueryCommandHandler(
     public async Task<RAGQueryResponse> Handle(RAGQueryCommand request, CancellationToken ct)
     {
         var kb = await db.KnowledgeBases.FindAsync([request.KnowledgeBaseId], ct)
-            ?? throw new NotFoundException("知识库不存在");
+                 ?? throw new NotFoundException("知识库不存在");
 
         // 检索流水线：向量化 -> 混合召回 -> 重排 -> 回填上下文
         var hits = await retrievalService.RetrieveAsync(kb, request.Question, ct);
@@ -52,4 +52,4 @@ public class RAGQueryCommandHandler(
         var answer = await chatAgent.RunAsync(ragMessages, ct);
         return new RAGQueryResponse(answer, sources);
     }
-}
+}