- New Economy.js price/stock engine: deterministic buy/sell prices based on
producer/demand classes and hop distance (regional availability model)
- Goods catalog (114 goods, 9 categories) with spritesheet mapping and
per-class producer/demand roles
- Credits state on Ship (add/spend/set/canAfford), save/restore support,
and upper-right HUD stacked above the minerals readout
- Quest reward payout now supports credits alongside minerals
- cargoHold reduced to 4 units for initial play balance
- Economy generation pass in Galaxy.js computes classBySystem and
producerHops via multi-source BFS over the jump network
- dev/economy.test.mjs validates determinism, fixed prices, trade loop
profitability, distance scaling, shop floor composition, and icon mapping
- docs/ECONOMY.md: full design doc covering pricing model, gemstone system,
and locked decisions
