removal of *temporary* collections

LightlessSync/LightlessConfiguration/Models/OrphanableTempCollectionEntry.cs

@@ -0,0 +1,7 @@
+namespace LightlessSync.LightlessConfiguration.Models;
+
+public sealed class OrphanableTempCollectionEntry
+{
+    public Guid Id { get; set; }
+    public DateTime RegisteredAtUtc { get; set; } = DateTime.MinValue;
+}