Integrate BLAS/TLAS acceleration structures and RT shadow compute pass
into the deferred rendering demo. Adds GpuContext::new_with_features()
for requesting EXPERIMENTAL_RAY_QUERY, Mesh::new_with_usage() for
BLAS_INPUT buffer flags, and extends the lighting shadow bind group
to 9 entries (shadow map + IBL + SSGI + RT shadow).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
tolelom
a5c0179793