切换批次和文件的 ID 类型为 UUID，更新相关逻辑和文档

internal/api/public/pickup.go

@@ -103,6 +103,11 @@ func (h *PickupHandler) Pickup(c *gin.Context) {
 		return
 	}
 
+	if batch.Type == "text" {
+		h.batchService.IncrementDownloadCount(batch.ID)
+		batch.DownloadCount++
+	}
+
 	c.JSON(http.StatusOK, model.SuccessResponse(PickupResponse{
 		Remark:        batch.Remark,
 		ExpireAt:      batch.ExpireAt,
@@ -119,24 +124,23 @@ func (h *PickupHandler) Pickup(c *gin.Context) {
 // @Summary      下载单个文件
 // @Description  根据文件 ID 下载单个文件
 // @Tags         Public
-// @Param        file_id  path  int  true  "文件 ID"
+// @Param        file_id  path  string  true  "文件 ID (UUID)"
 // @Produce      application/octet-stream
 // @Success      200  {file}    file
 // @Failure      404  {object}  model.Response
 // @Failure      410  {object}  model.Response
 // @Router       /api/files/{file_id}/download [get]
 func (h *PickupHandler) DownloadFile(c *gin.Context) {
-	fileIDStr := c.Param("file_id")
-	fileID, _ := strconv.ParseUint(fileIDStr, 10, 32)
+	fileID := c.Param("file_id")
 
 	var item model.FileItem
-	if err := bootstrap.DB.First(&item, fileID).Error; err != nil {
+	if err := bootstrap.DB.First(&item, "id = ?", fileID).Error; err != nil {
 		c.JSON(http.StatusNotFound, model.ErrorResponse(model.CodeNotFound, "file not found"))
 		return
 	}
 
 	var batch model.FileBatch
-	if err := bootstrap.DB.First(&batch, item.BatchID).Error; err != nil {
+	if err := bootstrap.DB.First(&batch, "id = ?", item.BatchID).Error; err != nil {
 		c.JSON(http.StatusNotFound, model.ErrorResponse(model.CodeNotFound, "batch not found"))
 		return
 	}

internal/api/public/upload.go

@@ -24,7 +24,7 @@ func NewUploadHandler() *UploadHandler {
 type UploadResponse struct {
 	PickupCode string     `json:"pickup_code"`
 	ExpireAt   *time.Time `json:"expire_at"`
-	BatchID    uint       `json:"batch_id"`
+	BatchID    string     `json:"batch_id"`
 }
 
 // Upload 上传文件并生成取件码