Install scripts using Nix to achieve cross-distros

This directory is currently WIP.
See also Install scripts | illogical-impulse
See also #1061

NOTE: The sdata/dist-nix is not for NixOS but every distro, using Nix and home-manager.

plan

Note that this script must be idempotent.

TODO:

Fix all TODOs inside dist-nix.
Warn user if inode-limited filesystem (typically ext4) is used.

Deal with error when running systemctl --user enable ydotool --now:

Failed to connect to user scope bus via local transport: $DBUS_SESSION_BUS_ADDRESS and $XDG_RUNTIME_DIR not defined (consider using --machine=<user>@.host --user to connect to bus of other user)

Attentions

PAM

On non-NixOS distros, programs using PAM (typically screen locker) will not work if installed via Nix, so user has to use their own distro's package for the screen lock.

One problem is that Debian(-based) distros use modified version of PAM which supports @include directive in /etc/pam.d config files but the PAM from Nix does not support it, see this comment.
Another problem is the location of a suid helper binary that is necessary, see this comment.

The problem could be solved by using the system-provided libpam instead.

NixGL

On non-NixOS distros, packages installed via home-manager have problem accessing GPU, especially Hyprland because it requires GPU acceleration to launch. nixGL should be used to address the problem.