media1: add NixOS media PC configuration

GMKtec G3 (Intel N100) replacing the old Ubuntu media PC on VLAN 31.
Hyprland compositor with Kodi on workspace 1 and Firefox on workspace 2,
greetd auto-login, PipeWire audio, VA-API hardware decode, and NFS
mount for media from NAS.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hosts/media1/default.nix

@@ -0,0 +1,7 @@
+{ ... }:
+{
+  imports = [
+    ./configuration.nix
+    ./media-desktop.nix
+  ];
+}