Clip hero cutout in MotionVectors pass to fix HTrace depth corruption

The MotionVectors pass (drawn by HTrace and URP against the real camera
depth buffer) was stock URP: no cutout clip and ZWrite on, so it wrote
the wall depth back into the hole after opaques. The skybox then failed
the depth test there (black disc) and all screen-space effects
(SSAO/GI) shaded the hole with the occluded wall's depth.

The pass now runs ApplyHeroCutout before URP's fragment entry point.
ObjectMotionVectors.hlsl forces its own entry via include_with_pragmas,
so the pragmas are declared explicitly and the file is plain-included.
Complements the earlier GBuffer clip; XR MV pass and ShadowCaster stay
stock on purpose. Includes render-queue churn on the occluder material.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/Materials/Hero Cutout Occluder.mat

@@ -16,7 +16,7 @@ Material:
   m_LightmapFlags: 4
   m_EnableInstancingVariants: 0
   m_DoubleSidedGI: 0
-  m_CustomRenderQueue: -1
+  m_CustomRenderQueue: 2000
   stringTagMap:
     RenderType: Opaque
   disabledShaderPasses: []

Assets/Unused/HeroCutoutLit.shader

@@ -4,7 +4,7 @@
 //
 // It is a faithful copy of URP's Lit.shader - same properties, keywords and includes, so material
 // values transfer 1:1 and the inspector GUI keeps working. The ONLY change is in four passes
-// (ForwardLit, ShadowCaster, DepthOnly, DepthNormals): the stock fragment entry point is replaced by
+// (ForwardLit, GBuffer, DepthOnly, DepthNormals): the stock fragment entry point is replaced by
 // a thin wrapper that runs ApplyHeroCutout() and then delegates to URP's original fragment. All
 // shading is therefore URP's own - zero reimplementation, so it stays correct across URP updates.
 Shader "Custom/HeroCutoutLit"
@@ -278,7 +278,7 @@ Shader "Custom/HeroCutoutLit"
             // -------------------------------------
             // Shader Stages
             #pragma vertex LitGBufferPassVertex
-            #pragma fragment LitGBufferPassFragment
+            #pragma fragment HeroGBufferFragment
 
             // -------------------------------------
             // Material Keywords
@@ -337,6 +337,17 @@ Shader "Custom/HeroCutoutLit"
             // Includes
             #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
             #include "Packages/com.unity.render-pipelines.universal/Shaders/LitGBufferPass.hlsl"
+            #include "HeroCutout.hlsl"
+
+            // Radial cutout, then delegate to URP's stock GBuffer fragment. Without this, external
+            // GBuffer consumers (HTrace WSGI renders its own thin GBuffer via this LightMode and
+            // composites GI after post-processing) still see solid occluder geometry inside the hole
+            // and stomp the visible skybox/background there with surface GI -> black disc.
+            GBufferFragOutput HeroGBufferFragment(Varyings input)
+            {
+                ApplyHeroCutout(input.positionCS);
+                return LitGBufferPassFragment(input);
+            }
             ENDHLSL
         }
 
@@ -540,12 +551,36 @@ Shader "Custom/HeroCutoutLit"
             ColorMask RG
 
             HLSLPROGRAM
+            // The cutout MUST also apply here: this pass has ZWrite On (default) and external
+            // consumers draw it against the LIVE camera depth attachment BEFORE the skybox
+            // (HTrace WSGI's object-motion-vectors pass at AfterRenderingOpaques). Without the
+            // clip it re-fills the hole with occluder depth -> the skybox fails ZTest inside the
+            // hole -> black disc, and the corrupted depth leaks into _CameraDepthTexture (SSAO/GI).
+            //
+            // ObjectMotionVectors.hlsl hardcodes "#pragma fragment frag" via include_with_pragmas,
+            // so we declare the pragmas ourselves and plain-#include it (plain includes contribute
+            // no pragmas), then wrap its frag().
+            #pragma target 3.5
+            #pragma vertex vert
+            #pragma fragment HeroMotionVectorsFragment
+
             #pragma shader_feature_local _ALPHATEST_ON
             #pragma multi_compile _ LOD_FADE_CROSSFADE
             #pragma shader_feature_local_vertex _ADD_PRECOMPUTED_VELOCITY
 
+            #pragma multi_compile_instancing
+            #include_with_pragmas "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DOTS.hlsl"
+            #include_with_pragmas "Packages/com.unity.render-pipelines.core/ShaderLibrary/FoveatedRenderingKeywords.hlsl"
+
             #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
-            #include_with_pragmas "Packages/com.unity.render-pipelines.universal/ShaderLibrary/ObjectMotionVectors.hlsl"
+            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/ObjectMotionVectors.hlsl"
+            #include "HeroCutout.hlsl"
+
+            float4 HeroMotionVectorsFragment(Varyings input) : SV_Target
+            {
+                ApplyHeroCutout(input.positionCS);
+                return frag(input);
+            }
             ENDHLSL
         }