neko: use real xfce image (software render), drop nonexistent nvidia-xfce + GPU

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

services/neko.nix

@@ -8,18 +8,19 @@
 # image (FROM the upstream nvidia-xfce base) instead of relying on a volume.
 # Guild Wars' own data installs into the persistent /home/neko volume on first run.
 #
-# GPU: uses the host's NVIDIA 535 driver via the container toolkit (CDI). The
-# Quadro M2000 does the GL rendering and NVENC video encode. If you ever see a
-# black screen or no video, the NVIDIA capabilities exposed to the container
-# (graphics + video) are the first thing to check — verify with:
-#   docker run --rm --device=nvidia.com/gpu=all neko-gw:local nvidia-smi
+# Rendering is software-only (no GPU): neko doesn't ship a prebuilt NVIDIA Xfce
+# desktop image, and building one from nvidia-base is a big detour for a 2005
+# game. Wine renders via llvmpipe (software OpenGL) and neko encodes via x264 —
+# both are heavily multithreaded and this box has 56 Xeon threads to spare, so
+# Guild Wars is comfortably playable this way.
 { config, pkgs, lib, ... }:
 let
   # Wine-enabled image definition. Fed to `docker build` over stdin (see below)
   # so there's no build context — we have no COPY/ADD, and a Nix-store symlinked
-  # context dir breaks BuildKit's Dockerfile resolution.
+  # context dir breaks BuildKit's Dockerfile resolution. Pinned to the v3.1
+  # series so the NEKO_MEMBER_*/NEKO_WEBRTC_* env schema below stays valid.
   dockerfile = pkgs.writeText "neko-gw.Dockerfile" ''
-    FROM ghcr.io/m1k1o/neko/nvidia-xfce:latest
+    FROM ghcr.io/m1k1o/neko/xfce:3.1
     USER root
     RUN dpkg --add-architecture i386 \
      && apt-get update \
@@ -32,8 +33,6 @@ in
   config = lib.mkIf (config.networking.hostName == "FredOS-Mediaserver") {
 
     virtualisation.docker.enable = true;
-    # Expose the host NVIDIA driver to containers via CDI (nvidia.com/gpu=all).
-    hardware.nvidia-container-toolkit.enable = true;
 
     systemd.tmpfiles.rules = [
       "d /var/lib/neko      0755 root root -"
@@ -66,9 +65,6 @@ in
         # (systemd's own ExecStart parser would strip the inner double quotes).
         ExecStart = pkgs.writeShellScript "neko-run" ''
           exec ${pkgs.docker}/bin/docker run --rm --name neko \
-            --device=nvidia.com/gpu=all \
-            -e NVIDIA_VISIBLE_DEVICES=all \
-            -e NVIDIA_DRIVER_CAPABILITIES=all \
             --shm-size=1g \
             -p 127.0.0.1:8092:8080 \
             -p 59000:59000/udp \