- The `retriedDynamic` latch test never made the retry fail: a real `listen(0)`
always succeeds, so it produced one EADDRINUSE and passed with the latch
deleted. Mock `node:http` so every listen fails, asserting exactly two listen
attempts and a settled result. Verified by mutation: removing the latch now
hangs the test instead of passing it.
- The migration guide's Docker notes still described a dynamic sandbox port and
told readers to pin a custom one, contradicting the new fixed 6275 two
sections later.
- Narrowed "or any container" in the troubleshooting entry, which overstated the
scope and contradicted the PR's own scope note. It now names the IPv4-forwarder
case and explicitly excludes the official image and a plain loopback -p.
Signed-off-by: cliffhall <cliff@futurescale.com>