Provider::Simplefin, Provider::Akahu and Provider::Up called
Kernel.sleep for retry backoff, which bypasses the instance-level
stubs(:sleep) the retry tests already set up - so the SimpleFIN retry
tests really slept through the 2s/4s/8s exponential backoff (16.8s for
the max-retries test alone, 23.5s for the suite).
Call sleep on the instance instead (same Kernel method, same behavior)
so mocha stubs take effect. The Simplefin with_retries sleep: keyword
is renamed to backoff: since it would shadow the method.
Provider::SimplefinTest drops from 23.5s to ~1s.
Claude-Session: https://claude.ai/code/session_01RpZe2ajeGkPRRBHfaJTfUB
Co-authored-by: Claude <noreply@anthropic.com>
8d649bc5b9