Circuit breakers: stop calling what's clearly broken

When the bank is clearly failing, stop calling it: the closed, open and half-open states, what counts as a failure, rate instead of count, fallbacks you can and can't fake, the thundering herd on recovery, servers that disagree, outages a breaker hides, and how breakers, retries and bulkheads stack with Day 1 timeouts and Day 2 idempotency.