`import =` and `export =` are really only intended for backwards
compatibility with CommonJS. While I really don't like the new module
system TC39 has designed for us, it's what we should be using, and
consistency is important.
`default` papers over AI logic errors. This change fixes those
errors instead:
- handle maybeDisabled/maybeTrapped properly
- use 0 PP and ally-less 'adjacentAlly' moves if necessary.
