Angular registers window message handlers via the
@HostListener('window:message', ['\']) decorator rather than
window.addEventListener('message', ...). The PostMessageEventHandler class
only modeled the addEventListener and window.onmessage forms, so the decorated
handler's event parameter was never treated as a message source. As a result,
js/missing-origin-check produced no alert and the event was not a client-side
remote flow source for downstream queries (e.g. client-side URL redirection).
Extend PostMessageEventHandler to also recognize methods decorated with
@HostListener for 'window:message', 'document:message', or 'message'.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
