fix(moonup): keep terminal open on errors via EXIT trap

The previous end-of-script `read` never ran when `set -e` aborted mid-way
(pacman conflict, paru failure, Ctrl+C), so foot closed on errors —
exactly when the user most needs to see the output.

Move the pause into a trap on EXIT, gated by `MOONUP_WAIT=1` so CLI use
stays non-interactive. Waybar on-click now sets the env var.

defaults/xdg/waybar/config

@@ -217,7 +217,7 @@
         },
         "exec": "moonarch-waybar-updates",
         "interval": 60,
-        "on-click": "foot moonarch-update"
+        "on-click": "foot env MOONUP_WAIT=1 moonarch-update"
     },
     "custom/notification": {
         "tooltip": true,

scripts/moonarch-update

@@ -19,6 +19,21 @@ _t() {
     esac
 }
 
+# Pause on exit when launched from a GUI (Waybar sets MOONUP_WAIT=1).
+# Runs via trap so it fires even when `set -e` aborts the script mid-way.
+_pause_on_exit() {
+    local rc=$?
+    if [[ -n "${MOONUP_WAIT:-}" && -t 0 ]]; then
+        echo
+        if (( rc != 0 )); then
+            echo -e "\e[1;31m[Moonarch ERROR]\e[0m $(_t "Exited with error (code $rc)" "Mit Fehler beendet (Code $rc)")" >&2
+        fi
+        read -n 1 -s -r -p "$(_t "Press any key to close..." "Beliebige Taste drücken zum Schließen …")" || true
+        echo
+    fi
+}
+trap _pause_on_exit EXIT
+
 # --- Helper functions ---
 
 log() {
@@ -120,9 +135,3 @@ log ""
 log "============================================"
 log "  $(_t "Moonarch update complete!" "Moonarch-Aktualisierung abgeschlossen!")"
 log "============================================"
-
-# Keep terminal open when launched from a GUI (e.g. Waybar on-click)
-if [[ -t 0 ]]; then
-    echo
-    read -n 1 -s -r -p "$(_t "Press any key to close..." "Beliebige Taste drücken zum Schließen …")"
-fi