Logging and reporting

ShadowJS does not log errors on its own; an ErrorBoundary shows its fallback and nothing else. Send errors to your reporter in one of three places:

1. The fallback, for failures that are shown: fallback={(error) => { report(error); return <Failed />; }}. The fallback is called once per error.

2. A root handler, for everything no boundary caught. catchError at the top of the tree sees errors from effects, memos and resources of the whole app:

3. The browser, for handlers and promises: window.addEventListener("error", ...) and window.addEventListener("unhandledrejection", ...).