Q#CT1-6: pure Lua on the Arc 2 substrate (effective-edit mutators,
command boundaries, after-edit delivery). M-; = comment-line-style
toggle (named deviation from comment-dwim); pmacs.comment.strings
public table; min-indent insertion, skip-blank, mixed-span comments;
single buf:replace per toggle = one undo step / one CRDT op / one
effective-edit verification.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>