feat(file): unify file handling with a new FileSource abstraction for URL and base64 data

middleware/body_cleanup.go

@@ -2,6 +2,7 @@ package middleware
 
 import (
 	"github.com/QuantumNous/new-api/common"
+	"github.com/QuantumNous/new-api/service"
 	"github.com/gin-gonic/gin"
 )
 
@@ -14,5 +15,8 @@ func BodyStorageCleanup() gin.HandlerFunc {
 
 		// 请求结束后清理存储
 		common.CleanupBodyStorage(c)
+
+		// 清理文件缓存（URL 下载的文件等）
+		service.CleanupFileSources(c)
 	}
 }