Manthano 3 and Planet Limit Fixes

[I_like_pie]

Note: this can be a marker for us to close manthano-3 in favor of a recurring econ-only galaxy.

There is an old topic about this, that is something we can actually do now if we want to. Please see below if interested:

Short econ race galaxy

How about a galaxy that runs for two weeks, which can be used purely for econ races? It would give players the chance to test and validate starting strategies, along with focussed training for new players on some key concepts. Typically, there’s only a chance to test a starting strategy once ever MW round. It would be great to do this more frequently - and add some competition to it. We have HC galaxies for attacking… here’s one for HC growth/econ!