Gitea Actions matrix: ubuntu-latest (py3.11/3.13) plus Debian 12,
Ubuntu 24.04, Fedora and Arch containers, each installing the system
libraries PySide6 wheels dlopen - all four validated locally in
Docker (Debian 141/141, QtWidgets import probe green everywhere).
Windows/macOS and a NixOS-FHS job (tools/ci-fhs.nix, the library set
from docs/NIXOS.md) are gated to github.com runners so they skip
instead of queueing forever here. README gets a Platform support
table with the workflow badge; KiCad-in-the-loop stays field-tested,
CI covers the solver and fallback suite.
