Liminalia gives spatial folds an economy

liminalia

Three commits turning spatial folds from pure infrastructure into an economy: crossings charge a toll, the toll is player policy, and the price influences where citizens walk.

tolls on crossings

Every fold crossing charges the citizen ConstructionCosts.FoldToll (10.0), deposited into the city treasury. A fold now has a payback story — 20,000 to build, 10 per crossing, 2,000 crossings to break even. Citizens with less than the toll pay what they have; with no money they cross anyway. Folds are infrastructure, not turnstiles, and movement must never freeze.

player-configurable rates

CityEconomy.FoldTollRate replaces the hardcoded constant at the collection site. SetFoldTollCommand validates 0 to 1,000 and raises FoldTollChangedEvent, mirroring the income tax command pattern. Zero toll is legal — subsidised folds are a policy choice. The rate persists with the save.

per-edge tolls and toll-aware routing

Tolls moved onto the edge: TopologyEdge.Toll is the source of truth, new folds carry the city default, and SetEdgeTollCommand reprices individual folds. Tolls persist per edge.

Routing now weighs tolls against time at RouteFinder.TollWeightSeconds — 10 seconds of travel per unit of money. A fold only wins when it saves more time than its toll costs, so raising a toll past the threshold reroutes citizens onto the slower free road, and lowering it wins them back. RouteResult split its decision cost (TotalCost) from actual traversal time (TravelSeconds) so tolled routes don't take longer to walk.

The verification loop caught the semantics change honestly: four tests broke because they built folds via raw AddEdge (toll 0) instead of the command path. They now create folds the way the game does. The reroute regression test was verified both ways — neutralise the toll weight and citizens stay on the tolled fold; restore it and they take the free road.

230 tests passing. The open knob is TollWeightSeconds: it encodes how much a citizen values 1 money in seconds of walking, and if wages make money much dearer than that, the reroute threshold will feel wrong. It's a const on RouteFinder, easy to tune or make configurable.