fix(web): calculate correct Hangfire job StartedAt using TotalDuration metadata

src/dotnet/QuantEngine.Web/Pages/Admin/Operations/Index.cshtml.cs

@@ -87,18 +87,26 @@ public class IndexModel : PageModel
             InactiveJobsCount = TotalJobsCount - ActiveJobsCount;
 
             var succeeded = monitoringApi.SucceededJobs(0, 10)
-                .Select(kv => new JobExecutionInfo(
+                .Select(kv => {
+                    var succeededAt = kv.Value.SucceededAt ?? DateTime.UtcNow;
+                    var durationMs = kv.Value.TotalDuration ?? 0;
+                    var startedAt = succeededAt.AddMilliseconds(-durationMs);
+                    return new JobExecutionInfo(
                         kv.Value.Job?.Method.Name ?? kv.Key,
-                    kv.Value.SucceededAt ?? DateTime.UtcNow,
+                        startedAt,
-                    kv.Value.SucceededAt,
+                        succeededAt,
-                    true));
+                        true);
+                });
 
             var failed = monitoringApi.FailedJobs(0, 10)
-                .Select(kv => new JobExecutionInfo(
+                .Select(kv => {
+                    var failedAt = kv.Value.FailedAt ?? DateTime.UtcNow;
+                    return new JobExecutionInfo(
                         kv.Value.Job?.Method.Name ?? kv.Key,
-                    kv.Value.FailedAt ?? DateTime.UtcNow,
+                        failedAt,
-                    kv.Value.FailedAt,
+                        failedAt,
-                    false));
+                        false);
+                });
 
             RecentExecutions = succeeded.Concat(failed)
                 .OrderByDescending(e => e.StartedAt)