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>

apps/web/src/hooks/useGameLoop.ts

@@ -0,0 +1,51 @@
+import { useEffect, useRef } from 'react';
+import { GameEngine } from '@ai-tycoon/game-engine';
+import { useGameStore } from '@/store';
+
+export function useGameLoop() {
+  const engineRef = useRef<GameEngine | null>(null);
+  const companyName = useGameStore((s) => s.meta.companyName);
+  const gameSpeed = useGameStore((s) => s.meta.gameSpeed);
+
+  useEffect(() => {
+    if (!companyName) return;
+
+    const engine = new GameEngine({
+      getState: () => {
+        const state = useGameStore.getState();
+        return {
+          meta: state.meta,
+          economy: state.economy,
+          infrastructure: state.infrastructure,
+          compute: state.compute,
+          research: state.research,
+          models: state.models,
+          market: state.market,
+          competitors: state.competitors,
+          talent: state.talent,
+          data: state.data,
+          reputation: state.reputation,
+          events: state.events,
+          achievements: state.achievements,
+        };
+      },
+      setState: (partial) => {
+        useGameStore.getState().updateState(partial);
+      },
+    });
+
+    engineRef.current = engine;
+    engine.start();
+
+    return () => {
+      engine.stop();
+      engineRef.current = null;
+    };
+  }, [companyName]);
+
+  useEffect(() => {
+    if (engineRef.current) {
+      engineRef.current.setSpeed(gameSpeed);
+    }
+  }, [gameSpeed]);
+}