feat: 文传易匿名临时文件传输站初始版本

- 后端 .NET 8 + FreeSql + 阿里云 OSS，支持共享/私密/标签三种文件模式
- 前端 Vue3 + Vite + TDesign，上传/取件/管理三页
- 取件码/二维码/海报合成（含保存二维码为图片）
- deploy/ 部署文档与一键 FTP 发布脚本
- appsettings.json 含真实凭据，已 gitignore 不入库

backend/WenChuanyi.Api/Controllers/AdminController.cs

@@ -0,0 +1,92 @@
+using Microsoft.AspNetCore.Mvc;
+using WenChuanyi.Api.Dtos;
+using WenChuanyi.Api.Models;
+using WenChuanyi.Api.Services;
+
+namespace WenChuanyi.Api.Controllers;
+
+/// <summary>发送者管理：凭管理码查看文件列表 / 删除文件</summary>
+[ApiController]
+[Route("api/admin")]
+public class AdminController : ControllerBase
+{
+    private readonly IFreeSql _fsql;
+    private readonly OssStorageService _oss;
+    private readonly ILogger<AdminController> _logger;
+
+    public AdminController(IFreeSql fsql, OssStorageService oss, ILogger<AdminController> logger)
+    {
+        _fsql = fsql;
+        _oss = oss;
+        _logger = logger;
+    }
+
+    /// <summary>管理码查询文件列表（含上传 IP）</summary>
+    [HttpGet("files/{adminCode}")]
+    public async Task<IActionResult> List(string adminCode)
+    {
+        if (string.IsNullOrEmpty(adminCode) || adminCode.Length != 8)
+        {
+            return BadRequest(new { message = "管理码无效" });
+        }
+        var list = await _fsql.Select<FileItem>()
+            .Where(f => f.AdminCode == adminCode)
+            .OrderByDescending(f => f.CreatedAt)
+            .ToListAsync();
+        return Ok(list.Select(ToDto));
+    }
+
+    /// <summary>删除指定文件（body 传 id 或取件码，校验管理码）</summary>
+    [HttpDelete("files/{adminCode}")]
+    public async Task<IActionResult> Delete(string adminCode, [FromBody] DeleteRequest? req)
+    {
+        if (string.IsNullOrEmpty(adminCode) || adminCode.Length != 8)
+        {
+            return BadRequest(new { message = "管理码无效" });
+        }
+        if (req == null || (req.Id == null && string.IsNullOrEmpty(req.PickCode)))
+        {
+            return BadRequest(new { message = "请提供要删除的文件 Id 或取件码" });
+        }
+
+        FileItem? item;
+        if (req.Id != null)
+        {
+            item = await _fsql.Select<FileItem>()
+                .Where(f => f.Id == req.Id.Value && f.AdminCode == adminCode).FirstAsync();
+        }
+        else
+        {
+            item = await _fsql.Select<FileItem>()
+                .Where(f => f.PickCode == req.PickCode && f.AdminCode == adminCode).FirstAsync();
+        }
+        if (item == null)
+        {
+            return NotFound(new { message = "文件不存在或管理码不匹配" });
+        }
+
+        var deleted = await _fsql.Delete<FileItem>().Where(f => f.Id == item.Id).ExecuteAffrowsAsync() > 0;
+        if (deleted)
+        {
+            _oss.TryDeleteObject(item.ObjectKey);
+        }
+        return Ok(new { message = "已删除" });
+    }
+
+    private static FileInfoDto ToDto(FileItem f) => new()
+    {
+        Id = f.Id,
+        PickCode = f.PickCode,
+        FileType = f.FileType,
+        HasPassword = f.FileType == "private",
+        OriginalName = f.OriginalName,
+        Size = f.Size,
+        MimeType = f.MimeType,
+        DownloadCount = f.DownloadCount,
+        UploadIp = f.UploadIp,
+        IsPermanent = f.IsPermanent,
+        ExpiresAt = f.ExpiresAt,
+        CreatedAt = f.CreatedAt,
+        ExpireText = FileRules.ExpireText(f)
+    };
+}