Document the intermittent connect-refused failure in the registrar
daemon test — root cause is the `daemon` fixture's blind `time.sleep()`
readiness gate racing against the subproc's `bind()`/ `listen()`
completion. Distinct from the cancel- cascade `TooSlowError` flake
class.
(this commit msg was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code