feat(blur): the brand logo cannot be blurred

The blur is universal, so it would swallow the logo along with everything else. The compositor
now defers every visible brand logo: skipped in both element loops, blitted immediately AFTER
the blur group, before the flash/social/ticker overlays. One logo per scene, so it is cheap.

Preview mirrors it: the staged scene's brand logo is drawn above the blur host (StagedBrandLogo),
so what you see in the editor is what the encoder gets.

Test: a blur covering the logo's area leaves the logo's pixels exactly white while the coloured
background beneath it blends.

Services/Compositor/SceneCompositor.cs

@@ -187,6 +187,9 @@ public sealed class SceneCompositor
                 case Source { IsBackground: true }:
                 case Source { Type: SourceType.Background }:
                 case Source { Type: SourceType.TextOverlay }:
+                // ⛔ The brand logo is drawn AFTER the blur group (creator ruling 2026-11-01):
+                // the blur is universal and must never hide the brand.
+                case Source { IsBrandLogo: true }:
                 case ZoomSceneElement { IsZoomActive: true }:
                     continue;
             }
@@ -201,6 +204,15 @@ public sealed class SceneCompositor
         // overlapping blurs still resolve to the strongest single one.
         ApplyBlurLayers(scene, buffer, cropW, cropH, options, timings);
 
+        // ⛔ The brand logo cannot be blurred (creator ruling 2026-11-01): it is blitted after the
+        // universal blur, so a privacy cover never swallows it. One per scene, so this is cheap.
+        foreach (var brand in scene.Elements.OfType<Source>().Where(s => s.IsBrandLogo && s.IsVisible))
+        {
+            var brandFrame = frameFor(brand);
+            if (brandFrame == null) continue;
+            BlitBakedElement(buffer, cropW, cropH, options, brand, brandFrame, timings, $"brand {brand.Name}");
+        }
+
         if (flashFrame != null)
         {
             var tFlash = System.Diagnostics.Stopwatch.GetTimestamp();
@@ -358,6 +370,9 @@ public sealed class SceneCompositor
                 case Source { IsBackground: true }:
                 case Source { Type: SourceType.Background }:
                 case Source { Type: SourceType.TextOverlay }:
+                // ⛔ The brand logo is drawn AFTER the blur group (creator ruling 2026-11-01):
+                // the blur is universal and must never hide the brand.
+                case Source { IsBrandLogo: true }:
                 case ZoomSceneElement { IsZoomActive: true }:
                     continue;
             }