Add Hono backend with PostgreSQL, auth, cloud saves, and leaderboard

Server app (apps/server) with Hono framework and Drizzle ORM:
- PostgreSQL schema: users, saves, leaderboard, achievements tables
- Anonymous auth with UUID tokens, optional email/password linking
- Cloud save API: list, get, upsert, delete with auto-save hook
- Leaderboard API: per-category rankings with score submission
- CORS configured for dev server ports
- Typed middleware with Hono env variables

Frontend cloud save integration:
- API client with auth token management in localStorage
- useCloudSave hook auto-saves every 300 ticks when authenticated
- Vite env type declarations for VITE_API_URL

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

apps/server/src/index.ts

@@ -0,0 +1,28 @@
+import { Hono } from 'hono';
+import { cors } from 'hono/cors';
+import { logger } from 'hono/logger';
+import { serve } from '@hono/node-server';
+import { auth } from './routes/auth';
+import { savesRouter } from './routes/saves';
+import { leaderboardRouter } from './routes/leaderboard';
+
+const app = new Hono();
+
+app.use('*', logger());
+app.use('*', cors({
+  origin: ['http://localhost:5173', 'http://localhost:5174', 'http://localhost:5175', 'http://localhost:5178'],
+  allowMethods: ['GET', 'POST', 'PUT', 'DELETE'],
+  allowHeaders: ['Content-Type', 'Authorization'],
+}));
+
+app.get('/health', (c) => c.json({ status: 'ok', version: '0.1.0' }));
+
+app.route('/api/auth', auth);
+app.route('/api/saves', savesRouter);
+app.route('/api/leaderboard', leaderboardRouter);
+
+const port = Number(process.env.PORT) || 3001;
+
+console.log(`AI Tycoon API server starting on port ${port}...`);
+
+serve({ fetch: app.fetch, port });