The simple economy is now the default and the old simulation is frozen as the hard model, selectable per game. A nation keeps one resource pool available in every region, fed by public production works rather than private per-region stores, and construction and training begin at once, paced by the region's spare power instead of gathering materials over days.
Money is euro only: a per-inhabitant daily tax funds a treasury spent in a global market, where buy and sell lots trade against the world stock and move its price. The hard economy keeps its per-nation currencies, central banks and exchange rates.
Simple games skip the price-settling warmup and economic migration; the snapshot carries the economy model, the market and the pool figures the client draws. Added the matching test suites and the design briefs under docs/simple_economy.
adrien