- Replace flat caps (CAR_CAP, HOUSE_CAP, BUILDING_CAP, WEEK_ROADS) with
per-stage values that scale over the run, preventing the week-6 growth
plateau where the expanded map stayed empty
- Add per-color starvation guards: ensure every unlocked colour has at
least 2 houses and 1 building, even if it means exceeding stage caps
- Allow spawnHouse/spawnBuilding to bypass caps when a colour is
supply-starved or destination-less
- Update bridge placement to handle 1-wide rivers (orientation-ambiguous
single-cell spans)
- Tune PIN_MS_MIN from 3500ms to 2400ms
- Extend Monte Carlo verification to 20 weeks with assertions that the
city grows past the old week-6 plateau