merge: bring main (UN-7, #140 filing, D.2b UI rows) into A7 Fix D round-2 branch

Resolves the divergence-register conflict: kept the accurate per-VERTEX AP-35
(Fix A shipped per-vertex; main's row was the stale pre-Fix-A per-pixel text),
kept main's UI rows AP-37..AP-42, and renumbered this branch's torch-gate row
AP-37 -> AP-43 (AP-37 was taken by main's LayoutDesc row). AP count 41 -> 42.
Retargeted the AP-37 references in WbDrawDispatcher + the CHECKPOINT to AP-43.
Marked ISSUES #140 RESOLVED (b7d655b) with the corrected root cause.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/AcDream.Core/Textures/SurfaceDecoder.cs

@@ -80,6 +80,11 @@ public static class SurfaceDecoder
     /// </summary>
     public static DecodedTexture DecodeSolidColor(DatReaderWriter.Types.ColorARGB color, float translucency)
     {
+        // Malformed Base1Solid (or OrigTextureId==0) surface with no color value:
+        // signal undecodable (Magenta) instead of NRE. This method is called
+        // directly from TextureCache.DecodeFromDats, OUTSIDE DecodeRenderSurface's
+        // try/catch, so it must be null-safe itself.
+        if (color is null) return DecodedTexture.Magenta;
         float opacity = Math.Clamp(1f - translucency, 0f, 1f);
         byte alpha = (byte)Math.Clamp(color.Alpha * opacity, 0f, 255f);
         return new DecodedTexture(