Launches a local headless Chromium and returns its CDP HTTP endpoint + teardown hook.
Per-session viewport hints (and the opaque backend configuration, unused here).
A handle carrying the launched browser's CDP HTTP endpoint and a Release that closes it.
The default local-Chrome runner — launches a local headless Chromium via Playwright and exposes its real CDP HTTP endpoint. Stateless; one instance is shared process-wide (each Acquire launches its own browser and its ChromeContainerHandle.Release closes exactly that one).