refactor: copy maintainer scripts instead of generating them

postinst

@@ -0,0 +1,11 @@
+#!/bin/sh
+set -e
+if [ "$1" = "configure" ] || [ "$1" = "abort-upgrade" ] || [ "$1" = "abort-deconfigure" ] || [ "$1" = "abort-remove" ]; then
+    if command -v gtk-update-icon-cache >/dev/null 2>&1; then
+        gtk-update-icon-cache -q -t -f /usr/share/icons/hicolor || true
+    fi
+    if command -v update-desktop-database >/dev/null 2>&1; then
+        update-desktop-database -q /usr/share/applications || true
+    fi
+fi
+exit 0