Add avahi, ipp-usb, udev (with sane‑airscan) and saned support.
Configure `sane` to enable extra backends (sane‑airscan) and disable the
default ESCL backend.
Override `simple-scan` to wrap its binary with an LD_LIBRARY_PATH that
includes `/etc/sane-libs`.
Remove per‑host printers.nix and merge printing settings into host
variables.
Add simple-scan package and enable it for desktop and laptop hosts.
Disable simple-scan for the default host.
Enable SANE daemon and expose its libraries in fish init.
Open required UDP ports 5353 and 54925 in network module.
Add printers.nix for Garand‑Desktop, Garand‑Laptop, and default hosts
with
printer definitions and a printEnable flag. Disable NFS by default in
the
host variables. Rewrite modules/core/printing.nix to import printer
settings, enable services only when printing is enabled, and add more
CUPS/Avahi options plus hardware.printers configuration. Add the lpadmin
group to the main user. Update the Messenger desktop entry URL to the
Facebook Messages page.
GarandPLG