Survive room upgrades automatically

Currently if mjolnir is protecting a room and it gets upgraded it doesn't protect the new room

So you have to manually remove the old room and add the new room

It would be great if mjolnir could notice a room upgrade and do this its self similar to how bridges can

Start by tracing how mjolnir currently handles protected rooms and how bridges detect room upgrades, as referenced in the issue. The work is done when protection automatically follows an upgraded room without requiring manual removal and re-adding.

Written by the indexing model from the issue text.