- Maps gain worldMap flag, description, freeform weather, latitude/longitude,
easeOfAccess and factionControl; picker cards render them as stat tags
- resource-nodes gain a shared icon set and may exist with no resources as
plain marker nodes (placement ignores marker-only nodes)
- sidebar gains the World Map entry; Infrastructure section gets defaultOpen
- migrations 20260921_120000/123000/130500/134000; includes the generated
types/schema sweep (currency emblem fields land in the next commit)
