The batches a session keeps for apps that reconnect were bounded only by count on a desktop host
and a private figcraft-server (`max_log_bytes` defaulted to usize::MAX). It now defaults to
64 MiB, and figcraft-server takes it from a new `max_log_mb` setting (default 64; open to the
public, also at most a quarter of `max_file_mb` as before). An app behind the trimmed log catches
up with a snapshot, as it already did past the count limits. The protocol is unchanged.
Nine 8 MiB renames with default limits: all 75.5 MB kept before, 58.7 MB after.
Fixes#1069
BFlat
436cfa1b96