Replace echo -e with printf for portable ANSI banners

dash (Debian's /bin/sh) doesn't support echo's -e flag: it prints "-e"
literally as text before processing the rest of the string's backslash
escapes. Every script's colored banner was affected. printf's escape
handling is POSIX-mandated and behaves identically under dash and bash,
so swap all 90 echo -e calls for printf, appending the trailing \n that
echo used to add implicitly.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

bin/upgrade.sh

@@ -2,13 +2,13 @@
 
 # TODO check if root
 
-echo -e '\033[35m
+printf '\033[35m
    __  ______  __________  ___    ____  ______
   / / / / __ \/ ____/ __ \/   |  / __ \/ ____/
  / / / / /_/ / / __/ /_/ / /| | / / / / __/
 / /_/ / ____/ /_/ / _, _/ ___ |/ /_/ / /___
 \____/_/    \____/_/ |_/_/  |_/_____/_____/
-\033[0m'
+\033[0m\n'
 
 if [ "$(id -u)" -ne 0 ]; then
   echo "Please run as root"