Reading state is now a per-(account,folder) floor plus an acked set of
UIDs above it, instead of a single monotonic pointer. This makes
acknowledgement per-message and order-independent so concurrent
subagents can process and ack out of order. Internal compaction collapses
contiguous acked runs into the floor to bound storage. Adds stateless
search and ack commands; reads no longer mutate state.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
steve
e3f8afbc7c