refactor: 移除不必要的配置依赖，简化上传URL生成逻辑并添加公开访问URL支持

internal/handler/user_handler.go

@@ -3,7 +3,6 @@ package handler
 import (
 	"carrotskin/internal/service"
 	"carrotskin/internal/types"
-	"carrotskin/pkg/config"
 	"carrotskin/pkg/database"
 	"carrotskin/pkg/logger"
 	"carrotskin/pkg/redis"
@@ -140,8 +139,7 @@ func GenerateAvatarUploadURL(c *gin.Context) {
 	}
 
 	storageClient := storage.MustGetClient()
-	cfg := *config.MustGetRustFSConfig()
-	result, err := service.GenerateAvatarUploadURL(c.Request.Context(), storageClient, cfg, userID, req.FileName)
+	result, err := service.GenerateAvatarUploadURL(c.Request.Context(), storageClient, userID, req.FileName)
 	if err != nil {
 		logger.MustGetLogger().Error("生成头像上传URL失败",
 			zap.Int64("user_id", userID),