fix: improve recovery and auto-start flows

src/LiveRecorder.Infrastructure/Services/FfmpegService.Utils.cs

@@ -80,7 +80,9 @@ public sealed partial class FfmpegService
         var stderrLines = new Queue<string>();
         var progressSync = new object();
         double? processedSeconds = null;
-        var lastReportedWholePercent = -1;
+        double? lastReportedProgressPercent = null;
+        string? lastReportedStage = null;
+        string? lastReportedDetail = null;
         var attemptStartedAt = DateTimeOffset.UtcNow;
         var activeStage = "Finalizing MP4";
         var maxDuration = TimeSpan.FromMinutes(Math.Clamp(mp4FinalizeTimeoutMinutes, 1, 1440));
@@ -114,19 +116,28 @@ public sealed partial class FfmpegService
                     detail = $"Processed {processedSeconds.Value:F1}s";
                 }
 
-                var wholePercent = progressPercent.HasValue ? (int)Math.Floor(progressPercent.Value) : -1;
-                if (stageOverride is null && wholePercent == lastReportedWholePercent)
+                var effectiveStage = stageOverride ?? activeStage;
+                var normalizedProgressPercent = progressPercent.HasValue
+                    ? Math.Round(progressPercent.Value, 1, MidpointRounding.AwayFromZero)
+                    : (double?)null;
+                var effectiveDetail = detail ?? $"Optimizing MP4 index for {Path.GetFileName(targetPath)}";
+
+                if (string.Equals(effectiveStage, lastReportedStage, StringComparison.Ordinal) &&
+                    string.Equals(effectiveDetail, lastReportedDetail, StringComparison.Ordinal) &&
+                    Nullable.Equals(normalizedProgressPercent, lastReportedProgressPercent))
                 {
                     return;
                 }
 
-                lastReportedWholePercent = wholePercent;
+                lastReportedStage = effectiveStage;
+                lastReportedDetail = effectiveDetail;
+                lastReportedProgressPercent = normalizedProgressPercent;
                 SetPostProcessState(
                     recordSessionId,
                     recordTaskId,
-                    stageOverride ?? activeStage,
-                    progressPercent,
-                    detail ?? $"Optimizing MP4 index for {Path.GetFileName(targetPath)}");
+                    effectiveStage,
+                    normalizedProgressPercent,
+                    effectiveDetail);
             }
         }
 
@@ -159,7 +170,9 @@ public sealed partial class FfmpegService
             ClearErrorDetail();
             activeStage = stage;
             processedSeconds = null;
-            lastReportedWholePercent = -1;
+            lastReportedProgressPercent = null;
+            lastReportedStage = null;
+            lastReportedDetail = null;
             attemptStartedAt = DateTimeOffset.UtcNow;
             System.Threading.Interlocked.Exchange(ref lastActivityTicks, attemptStartedAt.UtcTicks);
 

src/LiveRecorder.Infrastructure/Services/FfmpegService.cs

@@ -242,7 +242,7 @@ public sealed partial class FfmpegService : IFfmpegService
 
     public async Task<bool> TryReconcileInactiveSessionAsync(Guid recordSessionId, CancellationToken cancellationToken = default)
     {
-        if (IsRunning(recordSessionId) || IsSessionUnderPostProcessing(recordSessionId))
+        if (IsRunning(recordSessionId))
         {
             return false;
         }
@@ -269,11 +269,23 @@ public sealed partial class FfmpegService : IFfmpegService
             .ThenBy(static item => item.CreatedAt)
             .ToList();
 
-        var anyUsableOutput = false;
+        var anyUsableOutput = tasks.Any(static item => item.Status == RecordTaskStatus.Completed);
+        var hasBackgroundPostProcessing = false;
         string? sessionFinalizationError = null;
 
-        foreach (var task in tasks.Where(item => IsActiveTaskStatus(item.Status)))
+        foreach (var task in tasks)
         {
+            if (IsTaskUnderPostProcessing(task.Id))
+            {
+                hasBackgroundPostProcessing = true;
+                continue;
+            }
+
+            if (!IsActiveTaskStatus(task.Status))
+            {
+                continue;
+            }
+
             var durationSeconds = task.StartedAt.HasValue
                 ? (double?)Math.Max(0, (endedAt - task.StartedAt.Value).TotalSeconds)
                 : null;
@@ -299,6 +311,7 @@ public sealed partial class FfmpegService : IFfmpegService
             if (IsLowStoragePauseError(taskFinalizationError))
             {
                 task.MarkProcessing(taskFinalizationError, endedAt);
+                hasBackgroundPostProcessing = true;
             }
             else if (!string.IsNullOrWhiteSpace(taskFinalizationError))
             {
@@ -323,6 +336,12 @@ public sealed partial class FfmpegService : IFfmpegService
         {
             recordSession.MarkFailed(sessionFinalizationError, endedAt);
         }
+        else if (hasBackgroundPostProcessing)
+        {
+            recordSession.MarkStopped(
+                endedAt,
+                "Recording process was no longer running when the session was reconciled. Post-processing will continue in background.");
+        }
         else if (anyUsableOutput)
         {
             recordSession.MarkCompleted(endedAt);
@@ -594,8 +613,8 @@ public sealed partial class FfmpegService : IFfmpegService
     private void ClearPostProcessState(Guid recordTaskId) =>
         _postProcessStates.TryRemove(recordTaskId, out _);
 
-    private bool IsSessionUnderPostProcessing(Guid recordSessionId) =>
-        _postProcessStates.Values.Any(entry => entry.RecordSessionId == recordSessionId);
+    private bool IsTaskUnderPostProcessing(Guid recordTaskId) =>
+        _postProcessStates.ContainsKey(recordTaskId);
 
     private async Task<IDisposable> AcquireTranscodeSlotAsync(int maxConcurrentTasks, CancellationToken cancellationToken)
     {

src/LiveRecorder.Infrastructure/Services/LiveRoomPollingBackgroundService.cs

@@ -93,7 +93,14 @@ public sealed class LiveRoomPollingBackgroundService : BackgroundService
                 try
                 {
                     using var notificationScope = _serviceScopeFactory.CreateScope();
+                    var logService = notificationScope.ServiceProvider.GetRequiredService<ISystemLogService>();
                     var emailNotificationService = notificationScope.ServiceProvider.GetRequiredService<IEmailNotificationService>();
+                    await logService.WriteAsync(
+                        SystemLogLevel.Error,
+                        "Scheduler",
+                        "Background live room polling failed.",
+                        ex.ToString(),
+                        cancellationToken: CancellationToken.None);
                     if (ShouldSendExceptionEmail(BuildExceptionEmailKey("background-loop", ex)))
                     {
                         await emailNotificationService.SendExceptionAsync(