feat: New theme + wire price adjustement

public/js/engine/state.js

@@ -22,6 +22,7 @@ export function createState(ctx, now = Date.now()) {
     upgrades: [],
     savedAt: now,
     materialTimer: 0, // transient, never saved
+    materialTrend: 0, // transient: -1 falling, 0 steady, 1 rising
   };
 }
 
@@ -63,7 +64,7 @@ export function sanitizeState(raw, ctx, now = Date.now()) {
 
 /** Compact JSON (numbers trimmed to 10 significant digits) for cookies and export. */
 export function serializeState(state) {
-  const { materialTimer, ...persisted } = state;
+  const { materialTimer, materialTrend, ...persisted } = state;
   return JSON.stringify(persisted, (_key, value) =>
     typeof value === 'number' && Number.isFinite(value) ? Number(value.toPrecision(10)) : value,
   );