Pushes to main run the tests. The Deploy button publishes the Windows, RPM,
deb and F-Droid packages to the same NAS directories a dev machine uses, with
the same keys, then runs update-repo.sh, so public URLs don't change.
Builds run on Debian 12, in an image defined in ci/builder, so the Linux
packages now need glibc 2.36 instead of Fedora 44's 2.43.
