serialize_item_stack did not store the spoil percent and
deserialize_item_stack did not pass it to set_stack, so spoilable items
arrived fresh after a transfer. Store it when above 0 and restore it. The
percent is used instead of spoil_tick since tick counts differ between servers.
Co-authored-by: ILLISIS <jayson.harris01@gmail.com>
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
The role of a slave as a host for Factorio servers is not well reflected
in its name and has caused confusion among users. Rename slave to host
to better reflect its role as a host of Factorio servers.