Refactor pipeline state and render output abstractions

- Replace old pipeline enums/structs with new strongly-typed PipelineState and enums (ZTest, ZWrite, Cull, Blend, ColorWriteMask)
- Redesign pipeline keying: introduce 128-bit GraphicsPipelineKey, MaterialPipelineKey, and PassPipelineKey for robust PSO caching
- Replace IRenderTargetStrategy with IRenderOutput; add SwapChainRenderOutput and TextureRenderOutput
- Update renderer and window code to use new render output abstraction and handle viewport/scissor updates
- Make ShaderPass a readonly struct and Shader a struct; use ID-based pass lookup for efficiency
- Materials now support per-pass pipeline overrides with new keying
- Add defensive checks in D3D12CommandBuffer; update D3D12PipelineLibrary for new keying/state
- Move test shader to test.gsdef and update for new pipeline state syntax
- Remove obsolete files/interfaces and perform general code cleanups
- Update all usages and parsing logic for new pipeline state system

Ghost.Shader/Compiler/SDLCompiler.cs

@@ -128,20 +128,20 @@ internal static class SDLCompiler
         return $"{shader.name}_{pass.name}";
     }
 
-    private static PipelineDescriptor MeragePipeline(PipelineSemantic? semantic, PipelineDescriptor parent)
+    private static PipelineState MeragePipeline(PipelineSemantic? semantic, PipelineState parent)
     {
         if (semantic == null)
         {
             return parent;
         }
 
-        return new PipelineDescriptor
+        return new PipelineState
         {
-            zTest = semantic.zTest ?? parent.zTest,
-            zWrite = semantic.zWrite ?? parent.zWrite,
-            cull = semantic.cull ?? parent.cull,
-            blend = semantic.blend ?? parent.blend,
-            colorMask = semantic.colorMask ?? parent.colorMask
+            ZTest = semantic.zTest ?? parent.ZTest,
+            ZWrite = semantic.zWrite ?? parent.ZWrite,
+            Cull = semantic.cull ?? parent.Cull,
+            Blend = semantic.blend ?? parent.Blend,
+            ColorMask = semantic.colorMask ?? parent.ColorMask
         };
     }
 
@@ -208,7 +208,7 @@ internal static class SDLCompiler
         {
             foreach (var pass in semantics.passes)
             {
-                var localPipeline = MeragePipeline(pass.localPipeline, PipelineDescriptor.Default);
+                var localPipeline = MeragePipeline(pass.localPipeline, PipelineState.Default);
                 var fullPass = new FullPassDescriptor
                 {
                     uniqueIdentifier = GetPassUniqueId(semantics, pass),