fix: 优化后端各模块 handler

- database_handler, knowledge_handler, model_handler
- neo4j_handler, sub_table_handler
- system_handler, upload_handler
- knowledge_service, upload_service

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

server/internal/handler/upload_handler.go

@@ -20,7 +20,16 @@ func NewUploadHandler(uploadService *service.UploadService, knowledgeRepo *repos
 	return &UploadHandler{uploadService: uploadService, knowledgeRepo: knowledgeRepo}
 }
 
-// Upload 上传文件
+// @Summary 上传文件
+// @Description 上传文件到服务器（本地存储或MinIO）
+// @Tags 文件上传
+// @Accept multipart/form-data
+// @Produce json
+// @Param file formData file true "要上传的文件"
+// @Success 200 {object} map[string]interface{}
+// @Failure 400 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /api/file_upload [post]
 func (h *UploadHandler) Upload(c *gin.Context) {
 	file, err := c.FormFile("file")
 	if err != nil {
@@ -48,7 +57,16 @@ func (h *UploadHandler) Upload(c *gin.Context) {
 	c.JSON(http.StatusOK, result)
 }
 
-// Delete 删除文件
+// @Summary 删除文件
+// @Description 删除指定文件
+// @Tags 文件上传
+// @Accept json
+// @Produce json
+// @Param filename path string true "文件名"
+// @Success 200 {object} map[string]interface{}
+// @Failure 400 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /api/file_upload/{filename} [delete]
 func (h *UploadHandler) Delete(c *gin.Context) {
 	filename := c.Param("filename")
 	if filename == "" {
@@ -64,7 +82,17 @@ func (h *UploadHandler) Delete(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"success": true, "message": "File deleted"})
 }
 
-// ProxyFile 代理文件访问（解决 MinIO 内网地址和 HTTPS 问题）
+// @Summary 代理文件访问
+// @Description 代理访问文件，解决 MinIO 内网和 HTTPS 问题
+// @Tags 文件上传
+// @Accept json
+// @Produce octet-stream
+// @Param key query string true "文件Key"
+// @Param kb_id query string false "知识库ID"
+// @Success 200 {file} binary
+// @Failure 400 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /api/file_proxy [get]
 func (h *UploadHandler) ProxyFile(c *gin.Context) {
 	fileKey := c.Query("key")
 	kbID := c.Query("kb_id")