✨ feat(file-check): 添加 PLC 应答后命中文件删除

* 新增默认关闭的删除开关，仅在收到 PLC 放行应答后执行

* 本地与 SFTP Provider 校验根目录并支持幂等删除

* 补充工作流、设置页和文件删除相关测试与文档

src/AxiOmron.PcbCheck/Services/Implementations/LocalFileCheckProvider.cs

@@ -61,6 +61,33 @@ public sealed class LocalFileCheckProvider : IFileCheckProvider
         return await Task.Run(() => CheckInternal(barcode, config, cancellationToken), cancellationToken).ConfigureAwait(false);
     }
 
+    /// <summary>
+    /// 删除本地文件校验返回的精确命中文件。
+    /// 删除前会校验目标必须位于配置的本地根目录内，文件已不存在时按幂等成功处理。
+    /// </summary>
+    /// <param name="filePath">文件校验返回的精确命中文件路径。</param>
+    /// <param name="config">根配置对象。</param>
+    /// <param name="cancellationToken">取消令牌。取消后终止尚未完成的删除操作。</param>
+    /// <returns>文件删除结果。</returns>
+    public async Task<FileDeleteOutcome> DeleteFileAsync(string filePath, AppConfig config, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(config);
+        if (string.IsNullOrWhiteSpace(filePath))
+        {
+            return new FileDeleteOutcome
+            {
+                IsSuccess = false,
+                FilePath = filePath,
+                ErrorMessage = "待删除的本地产品 ID 文件路径为空。"
+            };
+        }
+
+        return await Task.Run(
+                () => DeleteInternal(filePath, config.FileCheck.Local.RootPath, cancellationToken),
+                cancellationToken)
+            .ConfigureAwait(false);
+    }
+
     /// <summary>
     /// 测试本地文件校验目录是否可访问。
     /// </summary>
@@ -129,6 +156,83 @@ public sealed class LocalFileCheckProvider : IFileCheckProvider
         }
     }
 
+    /// <summary>
+    /// 在同步上下文中安全删除本地产品 ID 文件。
+    /// </summary>
+    /// <param name="filePath">待删除文件路径。</param>
+    /// <param name="rootPath">配置的本地根目录。</param>
+    /// <param name="cancellationToken">取消令牌。</param>
+    /// <returns>文件删除结果。</returns>
+    private FileDeleteOutcome DeleteInternal(string filePath, string rootPath, CancellationToken cancellationToken)
+    {
+        cancellationToken.ThrowIfCancellationRequested();
+
+        try
+        {
+            string fullRootPath = Path.GetFullPath(rootPath);
+            string fullFilePath = Path.GetFullPath(filePath);
+            if (!IsPathWithinRoot(fullFilePath, fullRootPath))
+            {
+                return new FileDeleteOutcome
+                {
+                    IsSuccess = false,
+                    FilePath = fullFilePath,
+                    ErrorMessage = $"拒绝删除本地根目录之外的文件: {fullFilePath}"
+                };
+            }
+
+            if (!File.Exists(fullFilePath))
+            {
+                return new FileDeleteOutcome
+                {
+                    IsSuccess = true,
+                    WasAlreadyMissing = true,
+                    FilePath = fullFilePath
+                };
+            }
+
+            File.Delete(fullFilePath);
+            return new FileDeleteOutcome
+            {
+                IsSuccess = true,
+                FilePath = fullFilePath
+            };
+        }
+        catch (OperationCanceledException)
+        {
+            throw;
+        }
+        catch (Exception ex) when (ex is IOException
+                                   or UnauthorizedAccessException
+                                   or System.Security.SecurityException
+                                   or ArgumentException
+                                   or NotSupportedException)
+        {
+            _logger.LogError(ex, "删除本地产品 ID 文件异常，路径={FilePath}", true, filePath);
+            return new FileDeleteOutcome
+            {
+                IsSuccess = false,
+                FilePath = filePath,
+                ErrorMessage = $"删除本地产品 ID 文件失败: {ex.Message}"
+            };
+        }
+    }
+
+    /// <summary>
+    /// 判断目标文件是否位于配置根目录内，防止外部路径被误删。
+    /// </summary>
+    /// <param name="fullFilePath">目标文件绝对路径。</param>
+    /// <param name="fullRootPath">配置根目录绝对路径。</param>
+    /// <returns>目标位于根目录内返回 <see langword="true"/>；否则返回 <see langword="false"/>。</returns>
+    private static bool IsPathWithinRoot(string fullFilePath, string fullRootPath)
+    {
+        string relativePath = Path.GetRelativePath(fullRootPath, fullFilePath);
+        return !Path.IsPathRooted(relativePath)
+               && !string.Equals(relativePath, "..", StringComparison.Ordinal)
+               && !relativePath.StartsWith($"..{Path.DirectorySeparatorChar}", StringComparison.Ordinal)
+               && !relativePath.StartsWith($"..{Path.AltDirectorySeparatorChar}", StringComparison.Ordinal);
+    }
+
     /// <summary>
     /// 验证本地根目录配置和可访问性。
     /// </summary>