fix: D3D12 sphere rendering - correct matrix math, enable depth test, add texture sampling

- Fix TranslationMatrix to use correct indices (m12/m13/m14 for translation)
- Fix PerspectiveMatrix projection formula
- Enable depth testing (was disabled)
- Add texture sampling in pixel shader
- Adjust sphere radius to 1.0 and position to z=5
- Fix D3D12Buffer copy size calculation

tests/RHI/D3D12/integration/sphere/Res/Shader/sphere.hlsl

@@ -8,17 +8,25 @@ struct VSOut {
     float4 texcoord : TEXCOORD0;
 };
 
+Texture2D gDiffuseTexture : register(t0);
+SamplerState gSampler : register(s0);
+
 cbuffer MatrixBuffer : register(b0) {
-    float4x4 gMVP;
+    float4x4 gProjectionMatrix;
+    float4x4 gViewMatrix;
+    float4x4 gModelMatrix;
+    float4x4 gIT_ModelMatrix;
 };
 
 VSOut MainVS(Vertex v) {
     VSOut o;
-    o.pos = mul(gMVP, v.pos);
+    float4 positionWS = mul(gModelMatrix, v.pos);
+    float4 positionVS = mul(gViewMatrix, positionWS);
+    o.pos = mul(gProjectionMatrix, positionVS);
     o.texcoord = v.texcoord;
     return o;
 }
 
 float4 MainPS(VSOut i) : SV_TARGET {
-    return float4(1.0f, 0.0f, 0.0f, 1.0f);
+    return gDiffuseTexture.Sample(gSampler, i.texcoord.xy);
 }