Selkies and Sunshine conflict on Vast desktop; Selkies is a user systemd unit

On the Vast.ai Ubuntu Desktop (VM) template, running Sunshine at the same time as the built-in Selkies WebRTC desktop causes Selkies to hang on "waiting for stream" — they contend for the same X display capture and an NVENC encoder session on the (consumer) GPU. Fix: stop Sunshine, then restart Selkies so its GStreamer pipeline rebuilds with NVENC free. Selkies is NOT a system service and NOT under supervisor here; it is a USER systemd unit named selkies.service launched by /usr/local/bin/selkies-launcher.sh under systemd --user (uid 1000). Restart it with: sudo -u user XDG_RUNTIME_DIR=/run/user/1000 systemctl --user restart selkies.service, then reload the browser tab to re-initiate WebRTC. Selkies default encoder may be software x264enc; switch to nvh264enc in its side-panel UI (or SELKIES_ENCODER env) for hardware encoding. Note the Selkies path uses a bundled TURN server on the forwarded public IP:port, so it works without Tailscale. Separately: do NOT use the Linux Desktop *Container* template for gaming — it lacks Steam/Proton/Sunshine and its no-user-namespaces limit breaks Proton (pressure-vessel/bubblewrap); use the VM template for GTA V.