New backend op :streams (from seq high-water marks, so compacted streams still
list), threaded through mem-backend + durable serve/io-backend. catalog.sx:
persist/streams, stream-count, stream-exists?, total-events. 143/143.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
durable.sx: io-backend with an injectable transport — persist/durable-backend
performs each op as {:op "persist/..." :args (...)} (kernel suspends, host
resumes); persist/mock-durable services via persist/serve over an in-memory
disk. Identical request shapes mean the whole facet/projection/snapshot/
compaction stack runs unchanged on the durable backend. Crash/restart replay
recovers log+kv+snapshot. 91/91.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>