Add market feedback pricing

coalgov-wiki-pages/market.txt

@@ -26,7 +26,11 @@ Every traded material has a base price in config. The live price is adjusted by
 
   * If stock is low, the multiplier rises and items become more expensive.
   * If stock is high, the multiplier falls and items become cheaper.
+  * Recent net buying raises prices for a while.
+  * Recent net selling lowers prices for a while.
+  * Recent buy/sell pressure decays over time.
   * The config has minimum and maximum multipliers to prevent runaway prices.
+  * Materials can override the global target stock and multipliers under ''market.dynamic.materials''.
   * The buy price is higher than the sell price because the market has a spread.
 
 This keeps the economy simple while still reacting to player behavior. If everyone sells cobblestone, cobblestone becomes less valuable. If everyone buys out iron, iron becomes more expensive until players sell more into the market.
@@ -41,10 +45,25 @@ Food items start with Ministry stock 0 by default, so players must sell food int
     dynamic:
       initial_stock: 1024
       target_stock: 1024
+      elasticity: 1.0
+      stock_floor_ratio: 0.05
       min_multiplier: 0.35
       max_multiplier: 3.0
       sell_multiplier: 0.85
       buy_multiplier: 1.15
+      flow_half_life_minutes: 180
+      flow_weight: 0.5
+      flow_min_multiplier: 0.70
+      flow_max_multiplier: 1.75
+      materials:
+        COBBLESTONE:
+          target_stock: 4096
+          elasticity: 1.0
+          min_multiplier: 0.20
+          max_multiplier: 10.0
+          flow_weight: 1.25
+          flow_min_multiplier: 0.50
+          flow_max_multiplier: 2.25
     initial_stock:
       BREAD: 0
       COOKED_BEEF: 0