v0.3.0 — fail-early codec preflight + cross-distro multilib guidance

Standalone (GOG) HD cutscenes need a slice of the host's 32-bit userland that GE-Proton's codecs don't ship. This release makes that a fast, up-front stop instead of silent black cutscenes after a long install.

Highlights

• Fail-early 32-bit codec preflight (standalone installer): checks the required 32-bit libraries before any download and, if the host is missing them, prints the exact apt/dnf/pacman one-liner and stops. Pass --skip-codec-check to install anyway (audio-only cutscenes).
• Cross-distro coverage: package lists validated in Fedora 44, Ubuntu 24.04, Debian 13, and Arch containers; ostree/Bazzite-aware guidance.
• Fixes Fedora black cutscenes: stages libbz2.so.1.0 from Fedora's libbz2.so.1 (soname mismatch) and libvpx.so.6 (no distro ships that soname anymore).
• Docs: new "Get the installer" section so non-git users can download a tarball directly.

Get it (no git needed)

curl -fL https://github.com/psoetens/xwau-linux/archive/refs/tags/v0.3.0.tar.gz | tar xz
cd xwau-linux-0.3.0

Prebuilt Windows binaries are unchanged from v0.2.0 (carried forward here so this tag is self-contained).