Add Lua language support (gen_scripts)

[darkn3rd]

Add Lua (https://www.lua.org/) as a new language in lessons/gen_scripts/, alongside the existing awk/groovy/perl/php/python/ruby/tcl.

Based on tcl/ as the reference (interpreted, no build/link step - just scripts/ + Rakefile + psakefile.ps1, no Makefile):

• New lessons/gen_scripts/lua/ directory: Rakefile (imports shared testbox.rake), psakefile.ps1, scripts/ with one .lua file per lesson (~60 files mirroring tcl/'s/perl/'s set), README.md
• Add Lua to lessons/gen_scripts/{Brewfile,choco.config,cygwin_pkgs.txt,msys2_pkgs.txt,ubuntu2204_pkgs.txt} - package names confirmed: apt: lua5.4 (Ubuntu), cyg: lua (Cygwin), pacman: mingw-w64-ucrt-x86_64-lua (MSYS2, matching this project's existing UCRT64 convention for python/ruby/tcl), brew: lua (macOS)
• Windows: Chocolatey's lua package installs "Lua For Windows" (Lua 5.1, quite old) rather than a current 5.4/5.5 build - worth deciding whether that's acceptable or a manual-download script is needed instead, matching how other version-sensitive tools in this project are handled
• Add a Lua entry to the General Scripts area in scriptbox/scripts/verify_commands.rb's AREAS
• lessons/gen_scripts/README.md update

This is a full new-language port (~60 lesson files), so likely worth breaking into smaller PRs rather than one large one.