add the version script

version

@@ -0,0 +1,41 @@
+#!/bin/bash
+#
+# Purpose : Show which version of CoreDesktop this machine is running
+#
+# CoreDesktop is a rolling release, so its version is the date of the commit
+# the local checkout is on, plus the short hash to tell same-day commits apart,
+# e.g. 2026.10.22 (c5f0651). The kernel is shown separately because it comes
+# from Arch, not CoreDesktop.
+
+COREDESKTOP="$HOME/.local/share/coredesktop"
+
+source "$COREDESKTOP/utils.sh"
+
+if ! git -C "$COREDESKTOP" rev-parse --git-dir &> /dev/null; then
+  echo "CoreDesktop isn't installed in $COREDESKTOP."
+  exit 1
+fi
+
+version="$(git -C "$COREDESKTOP" log -1 --format='%cd (%h)' --date=format:%Y.%m.%d)"
+
+# Local edits to the checkout mean this isn't exactly the version above
+if [ -n "$(git -C "$COREDESKTOP" status --porcelain --untracked-files=no)" ]; then
+  version="$version, modified"
+fi
+
+kernel="$(uname -r)"
+# If the running kernel's modules are gone, a newer kernel was installed
+if [ ! -d "/usr/lib/modules/$kernel" ]; then
+  kernel="$kernel (newer kernel installed, reboot to use it)"
+fi
+
+# 10-pacman.sh rewrites this log on every update
+if [ -f "$PACMAN_UPDATE_LOG" ]; then
+  last_update="$(date -r "$PACMAN_UPDATE_LOG" '+%Y-%m-%d %H:%M')"
+else
+  last_update="never"
+fi
+
+echo "CoreDesktop  $version"
+echo "Kernel       $kernel"
+echo "Last update  $last_update"