The previous fix mocked SportIcon to render <img> elements. In jsdom, those
images fail to load and schedule async error callbacks that can stall React's
act() settlement loop when the full suite runs under load, causing the test to
hit the 5000ms timeout intermittently.
Replace the async mock factory with a trivial synchronous stub that returns
null — no images, no async events. resolveSportIconUrl URL resolution is
already covered by its own unit tests, so no coverage is lost.
https://claude.ai/code/session_012ACmUs2vAwEF9jZu7Guos2
40e1ba22b8