Add native cube render target support (re-enables 2 shadow-with-instances tests)

Render-to-cubemap on the native engine so ReflectionProbe and point-light
cube shadow maps render instead of dereferencing the null WebGL context.

- InitializeTexture: optional isCube param -> Texture::CreateCube.
- CreateFrameBuffer: optional layer param so the color attachment targets a
  single cube face (bgfx::Attachment layer); the JS side creates one
  framebuffer per face and binds the matching one per face.

Re-enables the "Shadows with instances in left/right handed system" validation
tests that previously crashed/hung.

Requires the paired Babylon.js change (native cube render target JS overrides);
CI stays red until a babylonjs npm with that change is published and the dep
bumped here.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bkaradzic

Apps/Playground/Scripts/config.json

@@ -1825,16 +1825,12 @@
             "title": "Shadows with instances in left handed system",
             "playgroundId": "#MSAHKR#79",
             "renderCount": 10,
-            "excludeFromAutomaticTesting": true,
-            "reason": "Test crashes or hangs on Babylon Native",
             "referenceImage": "shadowsinstancesleft.png"
         },
         {
             "title": "Shadows with instances in right handed system",
             "playgroundId": "#MSAHKR#13",
             "renderCount": 10,
-            "excludeFromAutomaticTesting": true,
-            "reason": "Test crashes or hangs on Babylon Native",
             "referenceImage": "shadowsinstancesright.png"
         },
         {

Plugins/NativeEngine/Source/NativeEngine.cpp

@@ -1321,6 +1321,7 @@ namespace Babylon
         const bool renderTarget = info[5].As<Napi::Boolean>();
         const bool srgb = info[6].As<Napi::Boolean>();
         const uint32_t samples = info[7].IsUndefined() ? 1 : info[7].As<Napi::Number>().Uint32Value();
+        const bool isCube = info.Length() > 8 && !info[8].IsUndefined() && info[8].As<Napi::Boolean>();
 
         auto flags = BGFX_TEXTURE_NONE;
         if (renderTarget)
@@ -1332,7 +1333,15 @@ namespace Babylon
             flags |= BGFX_TEXTURE_SRGB;
         }
 
-        texture->Create2D(width, height, hasMips, 1, format, flags);
+        if (isCube)
+        {
+            // Cube render target: width is the per-face size.
+            texture->CreateCube(width, hasMips, 1, format, flags);
+        }
+        else
+        {
+            texture->Create2D(width, height, hasMips, 1, format, flags);
+        }
     }
 
     void NativeEngine::LoadTexture(const Napi::CallbackInfo& info)
@@ -1820,6 +1829,8 @@ namespace Babylon
         const bool generateStencilBuffer = info[3].As<Napi::Boolean>();
         const bool generateDepth = info[4].As<Napi::Boolean>();
         const uint32_t samples = info[5].IsUndefined() ? 1 : info[5].As<Napi::Number>().Uint32Value();
+        // Optional cube-face / array layer for the color attachment (single-face cube render targets).
+        const uint16_t layer = (info.Length() > 6 && !info[6].IsUndefined()) ? static_cast<uint16_t>(info[6].As<Napi::Number>().Uint32Value()) : 0;
 
         std::array<bgfx::Attachment, 2> attachments{};
         uint8_t numAttachments = 0;
@@ -1830,7 +1841,7 @@ namespace Babylon
             // bgfx validation now asserts when trying to use BGFX_RESOLVE_AUTO_GEN_MIPS with a texture that doesn't have the BGFX_CAPS_FORMAT_TEXTURE_MIP_AUTOGEN flag,
             // but before it would just ignore the flag and not generate mips without any warning. This prevents validation assert, but rendering might be broken if autogen
             // mips were expected. Basically this change preserves previous behavior.
-            attachments[numAttachments++].init(texture->Handle(), bgfx::Access::Write, 0, 1, 0
+            attachments[numAttachments++].init(texture->Handle(), bgfx::Access::Write, layer, 1, 0
                 , 0 != (caps->formats[texture->Format()] & BGFX_CAPS_FORMAT_TEXTURE_MIP_AUTOGEN) ? BGFX_RESOLVE_AUTO_GEN_MIPS : BGFX_RESOLVE_NONE
                 );
         }