Release 0.4.1 - #198

This release contains no change to the application itself: it hardens the build and release pipeline
(the program is the same as 0.4.0).

CI/CD

• test-python-windows now gates the beta (it is in the needs of get-version-beta).
• The stable pipeline runs no tests, so find-latest-beta now also checks that main has the same
  code as the matching beta (only documentation may differ) and stops the release otherwise.
• New smoke test of the packages (scripts/smoke_sidecar.sh, .github/workflows/smoke-packages.yml): the
  .deb, .rpm and .tar.gz are installed on Ubuntu 24.04 and 26.04, Debian 13, Rocky Linux 9 and 10 and
  current Fedora, and the installed sidecar must start, require its token, read sample files of every format
  family and complete a write + undo round trip (the app's shared libraries must also resolve). The packaged
  Windows sidecar is exercised the same way. It gates both the beta and the stable release: nothing is
  published if a package is broken. The stable rebuilds its packages and tests those.

Documentation

• macOS: extended attributes stay read-only (stated in the requirements guide).