* fix(replication): count backlog at queue admission Co-Authored-By: heihutu <[email protected]> * feat(obs): expose bucket replication backlog gauges Co-Authored-By: heihutu <[email protected]> * fix(obs): report recent backlog from queued work Co-Authored-By: heihutu <[email protected]> * fix(obs): preserve legacy backlog metric semantics Co-Authored-By: heihutu <[email protected]> * feat(obs): expose durable MRF backlog gauges Co-Authored-By: heihutu <[email protected]> * test(obs): cover replication backlog metric scope Co-Authored-By: heihutu <[email protected]> * fix(obs): keep backlog metrics API-compatible Co-Authored-By: heihutu <[email protected]> * refactor(obs): streamline replication backlog metrics Keep MRF backlog accounting and OBS metric collection on a single, cheaper path. Co-Authored-By: heihutu <[email protected]> * test(kms): update aws capability snapshot Co-Authored-By: heihutu <[email protected]> --------- Co-authored-by: heihutu <[email protected]>