Check that every shorthand the www autoformat and basic marks kits declare applies whole when typed key by key, that no typed sequence of up to three keys changes a paragraph it was not typed in, that one undo takes back each keystroke that fires a rule, and that a key an input method commits gives what typing it gives. Use before and after changing apps/www/src/registry/components/editor/autoformat.tsx, basic-marks.tsx or another file in its coverage record, when the autoformat-rules step of pnpm check fails, or when fixing an autoformat or input-rule bug.