feat(middleware): scaffold Node.js/Express/TypeScript project with health endpoint

- package.json with express, better-sqlite3, mqtt, pg, bcrypt, jsonwebtoken, cors
- tsconfig.json targeting ES2022/commonjs
- src/index.ts with GET /health on port 4000
- vitest.config.ts for test runner configuration

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

display/middleware/src/index.ts

@@ -0,0 +1,20 @@
+import express from 'express';
+import cors from 'cors';
+
+const app = express();
+const PORT = process.env.PORT ? parseInt(process.env.PORT) : 4000;
+
+app.use(cors());
+app.use(express.json());
+
+app.get('/health', (_req, res) => {
+  res.json({ status: 'ok', timestamp: new Date().toISOString() });
+});
+
+if (require.main === module) {
+  app.listen(PORT, () => {
+    console.log(`Middleware server running on port ${PORT}`);
+  });
+}
+
+export default app;