* fix(startup): retry transient bucket metadata quorum failures
* fix(ecstore): retain recovered shard damage for read repair
* fix(ecstore): reconnect missing read sources before GET
* test(heal): prove exact marker replay preserves history
* fix(ecstore): fence reconnect retries at the deadline
Reject expired reconnect waiters before dispatch and start cooldown on sweep completion, including timeout and cancellation. Cover exact-deadline admission independently of cooldown and preserve the original strict RPC-count regression.