feat(02-01): BigQty + scheduler + sim foundations

- Install zustand@^5.0.0 + break_eternity.js@^2.1.3 as dependencies
- BigQty immutable wrapper around Decimal (D-31): factories,
  arithmetic, comparison, JSON round-trip, saturating coercion
- formatHumanReadable for K/M/B/T/scientific HUD readouts (UX-11)
- Clock interface + wallClock + FakeClock — only file in src/sim/
  allowed to read Date.now() (D-33)
- drainTicks fixed-timestep accumulator: refuses negative deltas
  (CORE-11), clamps at MAX_OFFLINE_MS=24h (CORE-03), TICK_MS=200
- computeOfflineCatchup pure descriptor for offline boundaries
- SimState root shape with BLOCKER 3 split: lastTickAt
  (wall-clock, app-layer-only) + tickCount (sim-internal monotonic)
- 52 tests across big-qty / format / clock / tick / catchup all green

package.json

@@ -16,6 +16,7 @@
     "ci": "npm run lint && npm run test && npm run validate:assets && npm run build"
   },
   "dependencies": {
+    "break_eternity.js": "^2.1.3",
     "crc-32": "^1.2.2",
     "gray-matter": "^4.0.3",
     "idb": "^8.0.3",
@@ -25,7 +26,8 @@
     "react": "^19.2.6",
     "react-dom": "^19.2.6",
     "yaml": "^2.8.4",
-    "zod": "^4.4.3"
+    "zod": "^4.4.3",
+    "zustand": "^5.0.13"
   },
   "devDependencies": {
     "@playwright/test": "^1.59.1",