feat: 完善知识库数据模型和服务

- 添加知识库更多字段配置
- 优化知识库服务逻辑
- 添加文档解析相关接口

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/cmd/api/main.go

@@ -98,7 +98,7 @@ func main() {
 	knowledgeHandler := handler.NewKnowledgeHandler(knowledgeService)
 	var uploadHandler *handler.UploadHandler
 	if uploadService != nil {
-		uploadHandler = handler.NewUploadHandler(uploadService)
+		uploadHandler = handler.NewUploadHandler(uploadService, knowledgeRepo)
 	}
 
 	// 7. 设置路由
@@ -216,6 +216,8 @@ func main() {
 		// 上传路由
 		r.POST("/api/file_upload", uploadHandler.Upload)
 		r.DELETE("/api/file_upload/:filename", uploadHandler.Delete)
+		// 文件代理路由（解决 MinIO 内网和 HTTPS 问题）
+		r.GET("/api/file_proxy", uploadHandler.ProxyFile)
 	}
 
 	// 8. 启动服务