The runtime-compat change in this branch added a `current_runtime`
kwarg to load_skills(); the watcher passes it through. Test mocks
that pre-date the kwarg signature broke with TypeError, which the
watcher's reload-error try/except swallowed — the symptom was empty
callback lists, not a clear failure.
Switching the fakes to accept **kwargs keeps them forward-compat for
future load_skills additions without another test churn.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>