0.13.0

Added

• A divergence survives the process that recorded it. Divergence serialises, and Hybrid::remember hands one back to a fresh Hybrid over the same stores, where catch_up replays it; the same divergence remembered twice is held once. For a shell that runs one process per command — a command-line tool keeping a plan in two stores — the divergence a write recorded can now be written beside the plan and acted on by the next command, rather than dying with the process that saw it.