test(coding-agent): pinned keyless premise in inherited shared-catalog abort test

- With a host ANTHROPIC_API_KEY (dev machines, agent harnesses) the
  anthropic manager gains a fetchDynamicModels hook whose endpoint fetch
  starts only after the catalog abort; its deadline timer arms after the
  test's last advanceTimersByTime, hanging the refresh forever under fake
  timers. Keyless CI never saw it.
- Spy authStorage.peekApiKey to undefined so the test reproduces the
  keyless CI premise on any host.