fix: sessions api with next engine

CHANGELOG.md

@@ -11,6 +11,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ### Fixed
 - Fix health checks causing a flood of (harmless) logged errors when quickly navigating away from home page
   - Health check results will now be cached for 5 minutes by default; a refresh button has been added to immediately re-run all checks
+- Fix `/api/sessions` response when channels use Next streaming engine
 
 ## [26.9.0] - 2026-09-06
 ### Fixed

ErsatzTV.Application/Streaming/NextSessionWorker.cs

@@ -87,15 +87,21 @@ public class NextSessionWorker(
 
     public Task<Option<TrimPlaylistResult>> TrimPlaylist(
         DateTimeOffset filterBefore,
-        CancellationToken cancellationToken) =>
-        throw new NotSupportedException();
+        CancellationToken cancellationToken)
+    {
+        logger.LogWarning(
+            "Legacy path called for next session worker on channel {Number}; this is NOT supported",
+            _channelNumber);
+
+        return Task.FromResult(Option<TrimPlaylistResult>.None);
+    }
 
     public void PlayoutUpdated()
     {
         // nothing to do here; channel binary should detect that by itself
     }
 
-    public HlsSessionModel GetModel() => throw new NotSupportedException();
+    public HlsSessionModel GetModel() => new(_channelNumber, "next", null, _lastTouch);
 
     public async Task Run(
         string channelNumber,

ErsatzTV.Core/FFmpeg/HlsSessionModel.cs

@@ -3,5 +3,5 @@ namespace ErsatzTV.Core.FFmpeg;
 public record HlsSessionModel(
     string ChannelNumber,
     string State,
-    DateTimeOffset TranscodedUntil,
+    DateTimeOffset? TranscodedUntil,
     DateTimeOffset LastAccess);