feat: 新增文件上传服务

- 添加 UploadHandler 处理文件上传
- 添加 UploadService 实现文件存储
- 配置上传文件大小限制和存储路径

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

server/cmd/api/main.go

@@ -82,6 +82,10 @@ func main() {
 	subTableService := service.NewSubTableService(subTableRepo, dbRepo)
 	neo4jService := service.NewNeo4jService(dbRepo)
 	modelService := service.NewModelService(modelRepo)
+	uploadService, err := service.NewUploadService(cfg)
+	if err != nil {
+		log.Printf("Warning: Failed to initialize upload service: %v (files will not be available)", err)
+	}
 
 	// 6. 初始化 Handler
 	dbHandler := handler.NewDatabaseHandler(dbService)
@@ -89,6 +93,10 @@ func main() {
 	neo4jHandler := handler.NewNeo4jHandler(neo4jService)
 	modelHandler := handler.NewModelHandler(modelService)
 	systemHandler := handler.NewSystemHandler()
+	var uploadHandler *handler.UploadHandler
+	if uploadService != nil {
+		uploadHandler = handler.NewUploadHandler(uploadService)
+	}
 
 	// 7. 设置路由
 	r := gin.New()
@@ -180,6 +188,17 @@ func main() {
 	// 系统信息模块
 	r.GET("/system/info", systemHandler.GetSystemInfo)
 
+	// 文件上传模块
+	if uploadHandler != nil {
+		// 本地文件静态服务
+		if cfg.UploadMode == "local" {
+			r.Static("/files", cfg.UploadLocalPath)
+		}
+		// 上传路由
+		r.POST("/upload", uploadHandler.Upload)
+		r.DELETE("/upload/:filename", uploadHandler.Delete)
+	}
+
 	// 8. 启动服务
 	log.Printf("Server starting on :%s", cfg.Port)
 	if err := r.Run(":" + cfg.Port); err != nil {