added barebones ui rendering

Shaders/ui.vert

@@ -0,0 +1,18 @@
+#version 440 core
+
+layout (location = 0) in vec2 aPos;
+layout (location = 1) in vec2 aTexCoord;
+layout (location = 2) in vec4 aColor;
+
+out vec2 TexCoord;
+out vec4 Color;
+
+uniform mat4 projection; // Ensure this name matches C# exactly
+
+void main() 
+{
+    // If you don't multiply by projection, the compiler deletes the uniform
+    gl_Position = projection * vec4(aPos, 0.0, 1.0);
+    TexCoord = aTexCoord;
+    Color = aColor;
+}