serve.mjs keeps the bound address as well as the port, so the settings,
queue and business routes answer a request that arrives after close().
browser.mjs keeps an exited leader's group tracked until it is killed at
exit, and close() signals the group only while the leader is alive. The
late-request test is event-based with one owned timeout. New test: the
chromium group dies when the main process dies and close() never runs.
Webui browser and server files (92, pinned-copy excluded): 741 pass, 0 fail.
jason.woltje
f9f34bd249