重构: 将 LogCleanupService 转为 Quartz Job 服务

- 创建 LogCleanupJob 替代 LogCleanupService (BackgroundService)
- 在 Expand.cs 中注册 LogCleanupJob (每天凌晨2点执行, 保留30天日志)
- 从 Program.cs 移除 LogCleanupService 的 HostedService 注册
- 删除 Service/LogCleanupService.cs
- 删除 Service/PeriodicBillBackgroundService.cs (已无用的重复服务)

所有后台任务现在统一通过 Quartz.NET 管理, 支持运行时控制

Service/Jobs/LogCleanupJob.cs

@@ -0,0 +1,78 @@
+using Quartz;
+
+namespace Service.Jobs;
+
+/// <summary>
+/// 日志清理定时任务
+/// </summary>
+[DisallowConcurrentExecution]
+public class LogCleanupJob(ILogger<LogCleanupJob> logger) : IJob
+{
+    private const int RetentionDays = 30; // 保留30天的日志
+
+    public Task Execute(IJobExecutionContext context)
+    {
+        try
+        {
+            logger.LogInformation("开始执行日志清理任务");
+
+            var logDirectory = Path.Combine(Directory.GetCurrentDirectory(), "logs");
+            if (!Directory.Exists(logDirectory))
+            {
+                logger.LogWarning("日志目录不存在: {LogDirectory}", logDirectory);
+                return Task.CompletedTask;
+            }
+
+            var cutoffDate = DateTime.Now.AddDays(-RetentionDays);
+            var logFiles = Directory.GetFiles(logDirectory, "log-*.txt");
+            var deletedCount = 0;
+
+            foreach (var logFile in logFiles)
+            {
+                try
+                {
+                    var fileName = Path.GetFileNameWithoutExtension(logFile);
+                    var dateStr = fileName.Replace("log-", "");
+
+                    // 尝试解析日期 (格式: yyyyMMdd)
+                    if (DateTime.TryParseExact(dateStr, "yyyyMMdd",
+                        CultureInfo.InvariantCulture,
+                        DateTimeStyles.None,
+                        out var logDate))
+                    {
+                        if (logDate < cutoffDate)
+                        {
+                            File.Delete(logFile);
+                            deletedCount++;
+                            logger.LogInformation("已删除过期日志文件: {LogFile} (日期: {LogDate})",
+                                Path.GetFileName(logFile), logDate.ToString("yyyy-MM-dd"));
+                        }
+                    }
+                }
+                catch (Exception ex)
+                {
+                    logger.LogError(ex, "删除日志文件失败: {LogFile}", logFile);
+                }
+            }
+
+            if (deletedCount > 0)
+            {
+                logger.LogInformation("日志清理完成,共删除 {DeletedCount} 个过期日志文件(保留 {RetentionDays} 天)",
+                    deletedCount, RetentionDays);
+            }
+            else
+            {
+                logger.LogDebug("没有需要清理的过期日志文件");
+            }
+
+            logger.LogInformation("日志清理任务执行完成");
+        }
+        catch (Exception ex)
+        {
+            logger.LogError(ex, "日志清理任务执行出错");
+            throw; // 让 Quartz 知道任务失败
+        }
+
+        return Task.CompletedTask;
+    }
+}