NeilClack
d661162676
Add a radiantwave-updater NixOS module that polls a manifest on the fileserver and swaps the app pointer /var/lib/radiantwave/current to new closures fetched from the dev Attic cache. Closures are fetched with 'nix copy --from', never built from source; the swap is atomic via mv -T. Enable it on the -dev variants only for now: the login shell launches from /var/lib/radiantwave/current/bin/radiantwave when enabled, and from the immutable system path otherwise, so prod behavior is unchanged. The pointer is seeded on first boot to the baseline copy already baked into the closure (no duplication).