The copy button and custom message actions only rendered on hover, so
they were unreachable by keyboard or assistive tech. Keep them in the
tree always — revealed via opacity on hover OR focus — and route each
through ClideTappable (Tab traversal + Enter/Space activation) with a
Semantics button label and onTap so AT can discover and invoke them.
alwaysIncludeSemantics keeps them in the semantics tree while hidden.
T-174.
Co-Authored-By: Claude <noreply@anthropic.com>