Building the renderer on Linux (CauldronGPU.Setup.Platform): a C++ compiler, make and
pkg-config, SDL3, Vulkan's headers, and a Vulkan driver to run it.
Looks in pkg-config's search, /usr/include, $VULKAN_SDK/include, LunarG's SDK
(~/vulkan/<version>/x86_64) and the setup's own folder. Installs through the
distribution's package manager (apt, dnf, pacman or zypper, run with sudo). Vulkan's
headers are downloaded instead, which needs no administrator rights; the renderer loads
the driver's Vulkan library when it runs. SDL3 is built from source into the setup's
folder where the distribution has no SDL3 package.