Extend nomarchy.services.* with three more opt-in toggles:
- podman: rootless containers, `docker` aliased to it, container DNS, and a
subuid/subgid range for the login user.
- flatpak: services.flatpak + a oneshot that adds the Flathub remote
system-wide (idempotent, retries when online).
- pika: ships pika-backup, the GUI for scheduled Borg backups.
Commented examples in the downstream system.nix template, per convention.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Start the opt-in services surface: nomarchy.services.{tailscale,syncthing},
off by default, in modules/nixos/services.nix. Tailscale ships the daemon
(authenticate with `sudo tailscale up`); Syncthing runs as the login user
with its GUI on 127.0.0.1:8384 (overrideDevices/Folders off so GUI-managed
folders survive rebuilds). username is read lazily, only when Syncthing is
on. Commented examples in the downstream system.nix template per the opt-in
convention.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
