- wiregrill.nix: filter out hosts with null wireguard pubkeys
- backup.nix: remove postgresqlBackup (no postgresql running)

- Remove ubik machine (DNS no longer points to us)
- Remove ubik-host.nix container config
- Remove sqlBackup.nix and mysql-backup module (no databases left)
- Remove usershadow module (was only used by removed exim auth)
- Clean up domsen.nix: remove dead domains, mail, users, backups
- Clean up util.nix: remove unused serveWordpress/serveOwncloud
- Clean up internet-gateway.nix: remove ubik domain routing
- Clean up exim-smarthost.nix: remove dead wordpress alias
- Clean up prism: remove mail.ubikmedia.eu proxy, usershadow

Domains removed (DNS pointed elsewhere):
- ubikmedia.de/eu, apanowicz.de, beesmooth.ch, jarugadesign.de
- jla-trading.com, alewis.de, freemonkey.art, aldonasiech.com
- karlaskop.de, youthtube.xyz, joemisch.com, weirdwednesday.de

Only illustra.de remains active on prism.

Uses services.upower for suspend on critical battery and a lightweight
systemd user service for espeak warnings. Removes krebs.power-action
dependency, special user, and sudo hacks.

Import moved from desktop configs to individual machine configs
(xerxes, ignavia) for explicit control.

- wrap firefox with native messaging hosts (tridactyl-native)
- add tridactylrc with superignore for my.sevdesk.de
- update browsers.nix to use the new firefox package

The libretro Dolphin core fails to initialize shader compiler worker
threads because CreateSharedContext() returns nullptr (libretro API
doesn't support creating additional GL contexts).

This patch disables background shader compilation in libretro builds,
forcing synchronous compilation which works correctly.

video-webcam: stream video/gif files to v4l2loopback with proper
aspect ratio handling (letterboxing instead of cropping)

android-webcam: remove lsmod check that failed in nix wrapper,
use device file checks instead