Force Direct3D11 for Windows builds to avoid paint-reseed crash

The build crashed natively (UnityPlayer, no managed frames) during the
match-end paint carry, where LoadPaintFromSnapshot/ReseedCanonical tears
down and rebuilds all RenderTextures with DrawMeshNow/Blit and ReadPixels
from LateUpdate, on multiple painters at once. D3D12 is far stricter than
D3D11 about this immediate-mode + RT-lifetime churn outside the render
loop. Pin the Windows standalone graphics API to D3D11 (D3D12 fallback)
as a mitigation without touching the paint architecture.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

ProjectSettings/ProjectSettings.asset

@@ -540,6 +540,9 @@ PlayerSettings:
   - m_BuildTarget: AndroidPlayer
     m_APIs: 150000000b000000
     m_Automatic: 0
+  - m_BuildTarget: WindowsStandaloneSupport
+    m_APIs: 0200000012000000
+    m_Automatic: 0
   m_BuildTargetVRSettings: []
   m_DefaultShaderChunkSizeInMB: 16
   m_DefaultShaderChunkCount: 0