refactor: best_effort log for quiet steps, registered temp dirs, one exit handler

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ss5gKj7XG5JPi27XwGBGTs

lib/menu.sh

@@ -446,7 +446,6 @@ draw_menu_tui() {
 run_menu_tui() {
     local cursor=0 key rest count
     tput civis 2>/dev/null
-    trap 'tput cnorm 2>/dev/null' EXIT
     while true; do
         draw_menu_tui "$cursor"
         count=${#MENU_ITEMS[@]}