fix(fish): persist remote system deployments

configs/nixos/modules/shell/fish/functions/deploy-to.fish

@@ -80,6 +80,13 @@ else
     echo "deploy-to: $host already has the full closure for $system_path" >&2
 end
 
+echo "deploy-to: recording $system_path as the system profile on $host" >&2
+ssh -t $host sudo nix-env --profile /nix/var/nix/profiles/system --set $system_path
+or begin
+    echo "deploy-to: system profile update failed for $host" >&2
+    return $status
+end
+
 echo "deploy-to: activating $system_path on $host" >&2
 ssh -t $host sudo "$system_path/bin/switch-to-configuration" switch
 or begin