Replace native GFN (impossible on this GPU) with browser GFN + Moonlight

The native GeForce NOW client hard-requires Vulkan video-decode
extensions (error 0xC0F11312) and the BC-250 has no video decode
hardware — unfixable at driver level. Replaced with:
- Chromium + a GeForce NOW web-app shortcut (works on Linux Chromium
  without UA tricks nowadays; CPU-decoded 1080p)
- Moonlight client for streaming from a home Sunshine host (planned:
  VM with RTX 3050 passthrough on the R730)
Drops bc250-gfn-install service/script.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

files/console/usr/bin/bc250-gfn-install

@@ -1,27 +0,0 @@
-#!/usr/bin/env bash
-# First-boot installer for the GeForce NOW native Linux app (beta).
-# GFN ships from NVIDIA's own flatpak repo, not Flathub, so the
-# default-flatpaks module can't handle it. Retries while the network
-# settles; stamps /var/lib/bc250/.gfn-installed on success so the
-# service never runs again.
-
-STAMP_DIR="/var/lib/bc250"
-STAMP="$STAMP_DIR/.gfn-installed"
-REPO_URL="https://international.download.nvidia.com/GFNLinux/flatpak/geforcenow.flatpakrepo"
-
-[ -f "$STAMP" ] && exit 0
-
-for attempt in $(seq 1 30); do
-    if flatpak remote-add --if-not-exists --system GeForceNOW "$REPO_URL" \
-       && flatpak install --system --noninteractive -y GeForceNOW com.nvidia.geforcenow; then
-        mkdir -p "$STAMP_DIR"
-        touch "$STAMP"
-        echo "GeForce NOW installed."
-        exit 0
-    fi
-    echo "GeForce NOW install attempt $attempt failed; retrying in 60s..."
-    sleep 60
-done
-
-echo "GeForce NOW install failed after 30 attempts; will retry next boot." >&2
-exit 1