Initial scaffold: AI Tycoon monorepo with core game loop

Turborepo monorepo with three packages:
- packages/shared: TypeScript types for all 14 game systems + balance constants + formatting utils
- packages/game-engine: Pure TS simulation engine with tick processor, economy, infrastructure, compute, research, market, and reputation systems
- apps/web: React + Vite + Tailwind + Zustand frontend with sidebar dashboard layout, new game screen, dashboard with charts, infrastructure management, and model training pages

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -0,0 +1,19 @@
+{
+  "name": "ai-tycoon",
+  "private": true,
+  "scripts": {
+    "dev": "turbo dev",
+    "build": "turbo build",
+    "typecheck": "turbo typecheck",
+    "lint": "turbo lint",
+    "clean": "turbo clean"
+  },
+  "devDependencies": {
+    "turbo": "^2.5.0",
+    "typescript": "^5.8.0"
+  },
+  "packageManager": "pnpm@10.33.0",
+  "pnpm": {
+    "onlyBuiltDependencies": ["esbuild"]
+  }
+}