submodule对gitea不管用，所以直接拉了一份拉格兰

Lagrange.Core/Lagrange.OneBot/Core/Entity/File/OneBotFile.cs

@@ -0,0 +1,29 @@
+using System.Text.Json.Serialization;
+
+namespace Lagrange.OneBot.Core.Entity.File;
+
+[Serializable]
+public class OneBotFile
+{
+    [JsonPropertyName("group_id")] public uint GroupId { get; set; }
+
+    [JsonPropertyName("file_id")] public string FileId { get; set; } = string.Empty;
+
+    [JsonPropertyName("file_name")] public string FileName { get; set; } = string.Empty;
+    
+    [JsonPropertyName("busid")] public int BusId { get; set; }
+    
+    [JsonPropertyName("file_size")] public ulong FileSize { get; set; }
+    
+    [JsonPropertyName("upload_time")] public uint UploadTime { get; set; }
+    
+    [JsonPropertyName("dead_time")] public uint DeadTime { get; set; }
+    
+    [JsonPropertyName("modify_time")] public uint ModifyTime { get; set; }
+    
+    [JsonPropertyName("download_times")] public uint DownloadTimes { get; set; }
+    
+    [JsonPropertyName("uploader")] public uint Uploader { get; set; }
+
+    [JsonPropertyName("uploader_name")] public string UploaderName { get; set; } = string.Empty;
+}

Lagrange.Core/Lagrange.OneBot/Core/Entity/File/OneBotFolder.cs

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+using System.Text.Json.Serialization;
+
+namespace Lagrange.OneBot.Core.Entity.File;
+
+[Serializable]
+public class OneBotFolder
+{
+    [JsonPropertyName("group_id")] public uint GroupId { get; set; }
+
+    [JsonPropertyName("folder_id")] public string FolderId { get; set; } = string.Empty;
+
+    [JsonPropertyName("folder_name")] public string FolderName { get; set; } = string.Empty;
+    
+    [JsonPropertyName("create_time")] public uint CreateTime { get; set; }
+    
+    [JsonPropertyName("creator")] public uint Creator { get; set; }
+    
+    [JsonPropertyName("create_name")] public string CreatorName { get; set; } = string.Empty;
+    
+    [JsonPropertyName("total_file_count")] public uint TotalFileCount { get; set; }
+}