fix: corregir renderizado de colores en prompts ask() y confirm()

read -rp no interpreta escapes ANSI — reemplazado por printf + read -r.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

rm-multiboot.sh

@@ -73,17 +73,20 @@ divider() { echo -e "\n  ${B}─────────────────
 ask() {
     local prompt="$1" default="${2:-}" answer
     if [[ -n "$default" ]]; then
-        read -rp "  ${W}$prompt${N} [$default]: " answer
+        printf "  ${W}%s${N} [%s]: " "$prompt" "$default"
+        read -r answer
         echo "${answer:-$default}"
     else
-        read -rp "  ${W}$prompt${N}: " answer
+        printf "  ${W}%s${N}: " "$prompt"
+        read -r answer
         echo "$answer"
     fi
 }
 
 confirm() {
     local answer
-    read -rp "  ${W}$* [s/N]:${N} " answer
+    printf "  ${W}%s [s/N]:${N} " "$*"
+    read -r answer
     [[ "${answer,,}" == "s" ]]
 }