notification service initial

system/update-check

@@ -0,0 +1,52 @@
+#!/bin/bash
+#
+# Purpose : Show a GNOME notification when a newer CoreDesktop is available.
+#           Clicking it (or its "Update now" button) runs update in a terminal.
+#           Run by coredesktop-update-check.timer (see system/update-notify.sh).
+
+# Wrapped in { ...; exit; } so bash reads the whole script up front; update
+# replaces this file (git pull) while the notification is waiting for a click.
+{
+
+# The newest version the user has been told about. Dismissing a notification
+# means not hearing about that version again, only about a newer one.
+NOTIFIED="$HOME/.local/state/coredesktop/update-notified"
+
+latest="$("$HOME/.local/bin/version" --check)" || exit 0
+[ "$(cat "$NOTIFIED" 2> /dev/null)" = "$latest" ] && exit 0
+
+# Waits until the notification is clicked or dismissed, then prints the action
+# ("default" is a click on the notification itself, empty if dismissed)
+action="$(notify-send --wait \
+  --app-name=CoreDesktop \
+  --icon=software-update-available \
+  --action=default=Update \
+  --action=update="Update now" \
+  "CoreDesktop update available" \
+  "Version $latest is ready. Click to run update.")" || exit 0
+
+mkdir -p "$(dirname "$NOTIFIED")"
+echo "$latest" > "$NOTIFIED"
+
+[ "$action" = "default" ] || [ "$action" = "update" ] || exit 0
+
+# Open the first terminal found. bash -i reads ~/.bashrc, as if the user had
+# typed update themselves, and the window stays open to show how it went.
+run_update=(bash -ic 'update; echo; read -rp "Press Enter to close this window."')
+if command -v xdg-terminal-exec &> /dev/null; then
+  terminal=(xdg-terminal-exec)
+elif command -v kgx &> /dev/null; then
+  terminal=(kgx --)
+elif command -v ghostty &> /dev/null; then
+  terminal=(ghostty -e)
+elif command -v kitty &> /dev/null; then
+  terminal=(kitty)
+else
+  notify-send --app-name=CoreDesktop "No terminal found" "Open a terminal and run update."
+  exit 1
+fi
+
+# Run the terminal as its own unit: when this service exits, systemd stops
+# everything still running in it, which would close the terminal mid-update
+exec systemd-run --user --quiet --collect -- "${terminal[@]}" "${run_update[@]}"
+}