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-lock.json

@@ -8,6 +8,7 @@
       "name": "the-last-garden",
       "version": "0.0.0",
       "dependencies": {
+        "break_eternity.js": "^2.1.3",
         "crc-32": "^1.2.2",
         "gray-matter": "^4.0.3",
         "idb": "^8.0.3",
@@ -17,7 +18,8 @@
         "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",
@@ -724,7 +726,7 @@
       "version": "19.2.14",
       "resolved": "https://registry.npmjs.org/@types/react/-/react-19.2.14.tgz",
       "integrity": "sha512-ilcTH/UniCkMdtexkoCN0bI7pMcJDvmQFPvuPvmEaYA/NSfFTAgdUSLAoVjaRJm7+6PvcM+q1zYOwS4wTYMF9w==",
-      "dev": true,
+      "devOptional": true,
       "license": "MIT",
       "dependencies": {
         "csstype": "^3.2.2"
@@ -1612,6 +1614,12 @@
         "node": ">=8"
       }
     },
+    "node_modules/break_eternity.js": {
+      "version": "2.1.3",
+      "resolved": "https://registry.npmjs.org/break_eternity.js/-/break_eternity.js-2.1.3.tgz",
+      "integrity": "sha512-4tg4j0wc0lhaYAnOHubN5mAyHbhMfUI7adQLO8l/loKqtylZ/kHWp8WYqG2EC0TinSesKvpCi3XeVFcKRUBJsQ==",
+      "license": "MIT"
+    },
     "node_modules/callsites": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/callsites/-/callsites-3.1.0.tgz",
@@ -1721,7 +1729,7 @@
       "version": "3.2.3",
       "resolved": "https://registry.npmjs.org/csstype/-/csstype-3.2.3.tgz",
       "integrity": "sha512-z1HGKcYy2xA8AGQfwrn0PAy+PB7X/GSj3UVJW9qKyn43xWa+gl5nXmU4qqLMRzWVLFC8KusUX8T/0kCiOYpAIQ==",
-      "dev": true,
+      "devOptional": true,
       "license": "MIT"
     },
     "node_modules/debug": {
@@ -4130,6 +4138,35 @@
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
       }
+    },
+    "node_modules/zustand": {
+      "version": "5.0.13",
+      "resolved": "https://registry.npmjs.org/zustand/-/zustand-5.0.13.tgz",
+      "integrity": "sha512-efI2tVaVQPqtOh114loML/Z80Y4NP3yc+Ff0fYiZJPauNeWZeIp/bRFD7I9bfmCOYBh/PHxlglQ9+wvlwnPikQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.20.0"
+      },
+      "peerDependencies": {
+        "@types/react": ">=18.0.0",
+        "immer": ">=9.0.6",
+        "react": ">=18.0.0",
+        "use-sync-external-store": ">=1.2.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "immer": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "use-sync-external-store": {
+          "optional": true
+        }
+      }
     }
   }
 }