Clarify the deadlock sink is not a product SLO: residual staging and coord
cleanup are best-effort GC, while safety remains CommittedResult and
StagingOwnership.
Drop LiveProgressAligned in favor of well-formedness and lease-compatible
progress, stop durable CAS from clearing Redis progress, and add ambient
ClearStaleLiveProgress so TLC matches Postgres + Dragonfly separation.
Replace tautological invariants with non-trivial ones, allow multi-shot
coordination loss and re-partition, fix reap/progress lifecycle, enable
deadlock checking via Done, and add stress and multi-shot TLC configs.
