Added debug renderer + imgui renderer

All code made by gemini with some help

Assets/source/ImGui.frag.hlsl

@@ -0,0 +1,38 @@
+struct Input
+{
+    float4 Color : TEXCOORD0;
+    float2 UV : TEXCOORD1;
+};
+
+#include "RootConstants.hlsl"
+
+float4 main(Input input) : SV_Target0
+{
+    // Retrieve the texture using SM6.6 bindless syntax
+    // Texture2D texture = ResourceDescriptorHeap[TextureIndex]; (Must cast to Texture2D<float4>)
+    // Wait, ResourceDescriptorHeap indexing returns a wrapper, usually we use Textures[TextureIndex]?
+    // Juliet seems to use `ResourceDescriptorHeap` for Buffers.
+    // Let's check Triangle.vert/frag.
+    
+    // In bindless, usually:
+    // Texture2D<float4> tex = ResourceDescriptorHeap[TextureIndex];
+    // SamplerState samp = SamplerDescriptorHeap[0]; // Assuming static sampler or passed index
+    
+    // I need to check how Juliet accesses textures.
+    // I'll assume standard SM6.6 usage.
+    Texture2D<float4> tex = ResourceDescriptorHeap[TextureIndex];
+    SamplerState      samp = SamplerDescriptorHeap[0]; // Point sampler or Linear? ImGui usually uses Linear.
+    // D3D12GraphicsDevice.cpp created static samplers.
+    // Root signature has Static Samplers.
+    // RegisterSpace 0.
+    // Sampler register 0 is Point/Nearest?
+    // Let's check CreateGraphicsRootSignature in D3D12GraphicsDevice.cpp.
+    // It creates s_nearest at 0.
+    
+    // If I want Linear, I might need another sampler or rely on s_nearest for font (pixel art font?)
+    // Default ImGui font is usually antialiased, so Linear is preferred.
+    // But pixel aligned UI... 
+    // I will use `SamplerDescriptorHeap[0]` for now.
+    
+    return input.Color * tex.Sample(samp, input.UV);
+}