win32 tool to generate shadercache

[CedricGuillemet]

I need this tool for a PoC. I'm wondering if it should be an independent tool instead (with Apple/Linux build) and NPM publishing.

[Copilot]

Pull request overview

Adds a new Win32 headless OpenGL/ANGLE app (ShaderCacheGenerator) to render a Babylon.js scene until shaders finish compiling, then persist the resulting ShaderCache to a file for reuse (e.g., GLES cache compatibility scenarios).

Changes:

• Introduces ShaderCacheGenerator executable that hosts a scene via Babylon::Embedding::Runtime/View, renders frames, and saves the shader cache.
• Adds build + usage documentation for the new tool.
• Wires the new app into the Apps CMake build under appropriate Win32/OpenGL + plugin/compiler feature gates.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
Apps/ShaderCacheGenerator/Source/Main.cpp	Implements the headless Win32 window + Embedding View render loop, readiness heuristic, and shader-cache persistence.
Apps/ShaderCacheGenerator/README.md	Documents purpose, usage, build, and “scene ready” heuristic.
Apps/ShaderCacheGenerator/CMakeLists.txt	Adds the new executable target, links required libraries, and copies runtime/ANGLE DLLs post-build.
Apps/CMakeLists.txt	Conditionally includes the ShaderCacheGenerator subdirectory for supported Win32/OpenGL configurations.