The reflect examples and the vulkan-utils-spirv test suite consumed
committed .spv files produced by out-of-band build-shaders.sh scripts,
which broke CI on a fresh checkout (the .spv were gitignored, and two
fixtures had no GLSL source at all). Shaders are now compiled at build
time by the vulkan-utils GLSL quasiquoters and reflected from the
embedded bytes; the scripts, shader files and file-embed dependency are
gone.

vulkan-utils-spirv gains the missing Bytes variants for the stage TH:
reflectStageSigBytes and reflectPipelineLayoutSigBytes, mirroring
reflectShaderTypesBytes.

Each example is restructured around per-pipeline modules whose
<Pipeline>.Shader submodule holds the quasiquoted SPIR-V (satisfying the
TH stage restriction) and whose pipeline module reflects it and builds
the pipeline; Main does the setup and Render the headless frame:

  * compute-reflect:   Main, Render, Julia(.Shader)
  * mesh-reflect:      Main, Render, Mesh(.Shader)
  * texture-reflect:   Main, Render, Tri(.Shader), Cube(.Shader)
  * pathtrace-reflect: Main, Render, Scene, Pathtracer(.Shader)

The pathtracer and bda shaders use compileShaderQ with a vulkan1.2
target (buffer_reference), wide.comp with vulkan1.1 (Int64). The
sourceless julia.comp and tri.vert fixtures are reconstructed from the
test suite's layout assertions, which pin them exactly.

All four examples render correctly (mesh/texture self-checks pass) and
the 75 vulkan-utils-spirv tests pass.

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