fix(spectrum): build the colour tables independently of KSH_ARRAYS

The table builder uses ${^codes} and the :^ zip flag, both of which
expand only element 0 when KSH_ARRAYS is set, leaving FG and BG empty.
The 256-iteration loop it replaced was option-independent.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

lib/spectrum.zsh

@@ -16,6 +16,7 @@ FX=(
 
 # Build the tables with array operations instead of a 256-iteration loop
 () {
+  setopt localoptions noksharrays
   local -a codes fg bg
   codes=({000..255})
   fg=( "%{"$'\e'"[38;5;"${^codes}"m%}" )