R-02: add an OPEN/DRAINING/CLOSED lifecycle orthogonal to freshness. Effect and
recovery authorities are now awaited under a deadline: on expiry the commit
capability is revoked and the work aborted, the caller gets a bounded
non-retryable IDLE_TIMEOUT, and the underlying task is retained rather than
dropped. A draining stream refuses new events and recovery, and close() returns
a Promise that succeeds only once every retained task actually settled,
reporting IDLE_TIMEOUT otherwise.
R-03: a handoff fail-close moves active, probe, quiescing and transition leases
into a retired-writer set before clearing their references, and close() waits on
current and retired writers together, so an abandoned non-cooperative writer can
no longer make teardown report a false success.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
