A selector like `foo]:has(*),body[x:value` previously produced
[foo]:has(*),body[x="..."], a syntactically valid CSS selector that
escaped the attribute match and selected `body`. Reject anything that
isn't a plain HTML attribute name.
Previous cssEscape only handled " and \, leaving NUL/newlines/control
chars to break out of the CSS string literal. Port the CSSOM string
serialization rules: NUL becomes U+FFFD, control chars become \HEX,
quotes/backslashes get escaped.
Class selector switched from `.x` (which would need separate identifier
escaping) to `[class~="x"]`, which is also semantically correct for
multi-class elements.
TapSelector now maps id:/desc:/descPrefix:/testTag:/etc. through
TranslateStringSelector. Unknown prefixes pass through to a CSS
attribute selector so a future Maestro key works without a release.
pj