feat(nvidia): evaluate shared NVIDIA system files for LTS

build_scripts/overrides/nvidia/20-nvidia.sh

@@ -100,6 +100,7 @@ EOF
 dnf config-manager --set-disabled nvidia-container-toolkit
 
 systemctl enable ublue-nvctk-cdi.service
+systemctl enable ublue-nvidia-flatpak-runtime-sync.service
 semodule --verbose --install /usr/share/selinux/packages/nvidia-container.pp
 
 # Universal Blue specific Initramfs fixes

docs/skills/hardware/SKILL.md

@@ -115,6 +115,17 @@ The `bluefin-lts-nvidia` variant ships full CDI configuration so `podman run --d
 
 ### NVIDIA CDI wiring
 
+**Shared NVIDIA files evaluated for LTS**
+
+| Shared file | LTS decision | Reason |
+|---|---|---|
+| `ublue-nvidia-flatpak-runtime-sync.service` | Included | CentOS Stream LTS ships Flatpak and systemd; the service is gated on the NVIDIA module and bootc runtime. |
+| `ublue-nvidia-flatpak-runtime-sync` | Included | Uses the standard Flatpak CLI and NVIDIA module version file; no Fedora-specific paths or package-manager assumptions. |
+
+The service and helper are copied into the LTS NVIDIA overlay and the service is
+explicitly enabled by `20-nvidia.sh`. Other shared NVIDIA files are not present
+in the current common layer and are not copied speculatively.
+
 **`build_scripts/overrides/nvidia/20-nvidia.sh`**
 ```bash
 # Configure nvidia-container-toolkit for rootless use.

system_files_overrides/nvidia/usr/lib/systemd/system/ublue-nvidia-flatpak-runtime-sync.service

@@ -0,0 +1,19 @@
+[Unit]
+Description=Sync NVIDIA system drivers with Flatpak runtime and update system Flatpaks
+After=network-online.target flatpak-system-helper.service
+Wants=network-online.target
+ConditionPathExists=/sys/module/nvidia/version
+# To not run on live ISO
+ConditionPathExists=/run/ostree-booted
+
+[Service]
+Type=oneshot
+ExecCondition=/usr/libexec/ublue-nvidia-flatpak-runtime-sync check
+ExecStart=/usr/libexec/ublue-nvidia-flatpak-runtime-sync sync
+RemainAfterExit=yes
+Restart=on-failure
+RestartSec=30
+TimeoutStartSec=900
+
+[Install]
+WantedBy=multi-user.target

system_files_overrides/nvidia/usr/libexec/ublue-nvidia-flatpak-runtime-sync

@@ -0,0 +1,36 @@
+#!/usr/bin/bash
+
+# Workaround for: https://github.com/flatpak/flatpak/issues/3907
+set -euo pipefail
+
+# NVIDIA_VERSION_FILE: override in tests to avoid reading real /sys
+NVIDIA_VERSION_FILE="${NVIDIA_VERSION_FILE:-/sys/module/nvidia/version}"
+
+SYSTEM_NVIDIA_VERSION=$(cat "${NVIDIA_VERSION_FILE}")
+FLATPAK_NVIDIA_VERSION=$(echo "${SYSTEM_NVIDIA_VERSION}" | tr '.' '-')
+
+case "${1:-}" in
+    check)
+        # Exit 0 if sync is needed (versions mismatch), exit 1 if already in sync
+        if flatpak info --system org.freedesktop.Platform.GL.nvidia-"${FLATPAK_NVIDIA_VERSION}" >/dev/null 2>&1 && \
+           flatpak info --system org.freedesktop.Platform.GL32.nvidia-"${FLATPAK_NVIDIA_VERSION}" >/dev/null 2>&1; then
+            echo "NVIDIA Flatpak runtime ${SYSTEM_NVIDIA_VERSION} already installed"
+            exit 1
+        fi
+        echo "NVIDIA Flatpak runtime ${SYSTEM_NVIDIA_VERSION} needs to be installed"
+        exit 0
+        ;;
+    sync)
+        echo "Installing NVIDIA Flatpak runtime version ${SYSTEM_NVIDIA_VERSION}"
+        flatpak remote-add --system --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
+        flatpak install --system --noninteractive -y flathub \
+            org.freedesktop.Platform.GL.nvidia-"${FLATPAK_NVIDIA_VERSION}" \
+            org.freedesktop.Platform.GL32.nvidia-"${FLATPAK_NVIDIA_VERSION}"
+        echo "Updating system Flatpaks after NVIDIA driver change"
+        flatpak update --system --noninteractive -y
+        ;;
+    *)
+        echo "Usage: $0 {check|sync}"
+        exit 1
+        ;;
+esac