configurator: drain tty input after each step() title

gum's TUI startup queries the terminal (e.g., cursor position via
CSI 6n) and doesn't always read the reply. The reply bytes
("^[[13;1R") then surface visibly next to the next step title.
A one-time drain at script start (in .automated_script.sh) catches
the boot-time replies but not the gum-per-call ones, since the
artifact came back at every new step().

Add a small _drain_tty helper and call it from step() after the
title gum-style invocation so any pending DSR replies are consumed
before the next prompt runs.

configs/airootfs/root/configurator

@@ -13,10 +13,18 @@ abort() {
   exit 1
 }
 
+# Drain any pending terminal-reply bytes (cursor position reports, etc.)
+# that gum's TUI startup sends but doesn't always consume. Without this,
+# bytes like ^[[13;1R show up next to step titles.
+_drain_tty() {
+  while IFS= read -r -t 0 -n 1024 _drain </dev/tty 2>/dev/null; do :; done
+}
+
 step() {
   clear_logo
   echo
   gum style "$1"
+  _drain_tty
   echo
 }