refactor: update knowledge base index removal method for improved clarity and efficiency

internal/services/knowledge_base_service.go

@@ -137,11 +137,11 @@ func (s *knowledgeBaseService) DeleteKnowledgeBase(id int64) error {
 		return errorsx.Forbidden(fmt.Sprintf("知识库已被 %d 个 AI Agent 引用，请先解除绑定", len(referencingAgents)))
 	}
 
-	chunks := repositories.KnowledgeChunkRepository.Find(sqls.DB(), sqls.NewCnd().Eq("knowledge_base_id", id))
+	if err := rag.Index.RemoveKnowledgeBaseIndex(context.Background(), id); err != nil {
+		return err
+	}
+
 	if err := sqls.WithTransaction(func(ctx *sqls.TxContext) error {
-		if err := repositories.KnowledgeChunkRepository.DeleteByKnowledgeBaseID(ctx.Tx, id); err != nil {
-			return err
-		}
 		if err := repositories.KnowledgeDocumentRepository.DeleteByKnowledgeBaseID(ctx.Tx, id); err != nil {
 			return err
 		}
@@ -153,7 +153,7 @@ func (s *knowledgeBaseService) DeleteKnowledgeBase(id int64) error {
 		return err
 	}
 
-	return rag.Index.RemoveKnowledgeBaseIndexByChunkModels(context.Background(), id, chunks)
+	return nil
 }
 
 func (s *knowledgeBaseService) UpdateSort(ids []int64) error {