Rename shaders and improve Wayland support
- Rename shader files to use .vert, .frag, and .comp extensions.
- Update shader compiler to handle new extensions and varying definitions.
- Implement proper Wayland detection and native handle retrieval in get-natives.cpp.
- Update asset loading paths across the codebase to match new shader filenames.
- Pass correct NativeWindowHandleType to bgfx during initialization.
- Mark several respawn point and crafting table tasks as completed in todo.md.