feat: initialize Annual Gala Interactive System monorepo

- Set up pnpm workspace with 4 packages: shared, server, client-mobile, client-screen
- Implement Redis atomic voting with Lua scripts (HINCRBY + distributed lock)
- Add optimistic UI with IndexedDB queue for offline resilience
- Configure Socket.io with auto-reconnection (infinite retries)
- Separate mobile (Vant) and big screen (Pixi.js) dependencies

Tech stack:
- Frontend Mobile: Vue 3 + Vant + Socket.io-client
- Frontend Screen: Vue 3 + Pixi.js + GSAP
- Backend: Express + Socket.io + Redis + Prisma/MySQL

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

packages/server/src/app.ts

@@ -0,0 +1,52 @@
+import express, { Application } from 'express';
+import cors from 'cors';
+import helmet from 'helmet';
+import compression from 'compression';
+import { config } from './config';
+import { logger } from './utils/logger';
+import { errorHandler } from './middleware/errorHandler';
+import { requestLogger } from './middleware/requestLogger';
+import voteRoutes from './routes/vote.routes';
+import adminRoutes from './routes/admin.routes';
+
+export const app: Application = express();
+
+// Security middleware
+app.use(helmet());
+
+// CORS
+app.use(
+  cors({
+    origin: config.corsOrigins,
+    credentials: true,
+  })
+);
+
+// Compression
+app.use(compression());
+
+// Body parsing
+app.use(express.json({ limit: '1mb' }));
+app.use(express.urlencoded({ extended: true }));
+
+// Request logging
+app.use(requestLogger);
+
+// Health check
+app.get('/health', (_req, res) => {
+  res.json({ status: 'ok', timestamp: new Date().toISOString() });
+});
+
+// API routes
+app.use('/api/vote', voteRoutes);
+app.use('/api/admin', adminRoutes);
+
+// 404 handler
+app.use((_req, res) => {
+  res.status(404).json({ error: 'Not Found' });
+});
+
+// Error handler
+app.use(errorHandler);
+
+export { logger };