fix(blur): the crash on launch — BlurAmount was in the INSERT and the reader, not the SELECT

LayoutStore.Load threw ArgumentOutOfRangeException on GetOrdinal("BlurAmount") during the
MainViewModel constructor, so the app died at startup rather than when a blur was used. The
migration adds the column and Save writes it; the reading query still listed its columns
explicitly and BlurAmount was missing from that list.

Adds LayoutBlurPersistenceTests: a blur saved and reloaded, asserting the amount and geometry
survive. That is the test that should have existed with the feature — the startup path it
covers has no other guard.

Services/LayoutStore.Load.cs

@@ -111,7 +111,7 @@ public partial class LayoutStore : IDisposable
                        ChatShowTimestamps, ChatShowBadges, ChatMemberColor, ChatSuperChatColor,
                        WebUri, MediaPath, MediaIsLooping, MediaVolume, MediaPlaybackState,
                        AlertVideoAssetId, AlertVideoPath, AlertUseDefaultVideo, AlertShowTicker, AlertVideoVolume, SortOrder,
-                       AlertDisplayMethod, IsBrandLogo
+                       AlertDisplayMethod, IsBrandLogo, BlurAmount
                 FROM Source ORDER BY SortOrder
                 """;
             using var reader = cmd.ExecuteReader();

ytLive.Tests/LayoutBlurPersistenceTests.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.ObjectModel;
+using System.IO;
+using System.Linq;
+using Xunit;
+using ytLive.Models;
+using ytLive.Services;
+
+namespace ytLive.Tests;
+
+/// <summary>
+/// The blur column round-trips through SQLite (2026-11-01). This exists because the first cut
+/// added `BlurAmount` to the INSERT and the reader but not to the SELECT — the app then crashed on
+/// launch inside `GetOrdinal("BlurAmount")`, which is a startup path no other test covers.
+/// </summary>
+public class LayoutBlurPersistenceTests
+{
+    [Fact]
+    public void A_blur_layer_survives_a_save_and_reload_with_its_amount()
+    {
+        var dbPath = Path.Combine(Path.GetTempPath(), $"llamacasty-blur-{Guid.NewGuid():N}.db");
+        try
+        {
+            var scenes = new ObservableCollection<Scene>
+            {
+                new() { Name = SceneCatalog.Live },
+            };
+            var background = new Source { Name = "Background", Type = SourceType.Background, IsBackground = true, Width = 1920, Height = 1080 };
+            var blur = new Source { Name = "Blur", Type = SourceType.Blur, X = 40, Y = 50, Width = 240, Height = 160, BlurAmount = 0.8 };
+            scenes[0].Elements.Add(background);
+            scenes[0].Elements.Add(blur);
+
+            using (var store = new LayoutStore(dbPath))
+                store.Save(scenes, null, null);
+
+            using (var reopened = new LayoutStore(dbPath))
+            {
+                var loaded = reopened.Load();
+                var loadedBlur = loaded.SelectMany(s => s.Elements).OfType<Source>().Single(s => s.Type == SourceType.Blur);
+                Assert.Equal(0.8, loadedBlur.BlurAmount, 3);
+                Assert.Equal(240, loadedBlur.Width, 3);
+                Assert.Equal(SourceType.Blur, loadedBlur.Type);
+            }
+        }
+        finally
+        {
+            try { File.Delete(dbPath); } catch (IOException) { }
+        }
+    }
+}