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/package.json

@@ -0,0 +1,36 @@
+{
+  "name": "display-middleware",
+  "version": "1.0.0",
+  "description": "Middleware backend for ESP32 e-paper display system",
+  "main": "dist/index.js",
+  "scripts": {
+    "dev": "tsx watch src/index.ts",
+    "build": "tsc",
+    "start": "node dist/index.js",
+    "test": "vitest run",
+    "test:watch": "vitest"
+  },
+  "dependencies": {
+    "bcrypt": "^5.1.1",
+    "better-sqlite3": "^9.6.0",
+    "cors": "^2.8.6",
+    "express": "^4.22.1",
+    "jsonwebtoken": "^9.0.3",
+    "mqtt": "^5.15.1",
+    "pg": "^8.20.0"
+  },
+  "devDependencies": {
+    "@types/bcrypt": "^5.0.2",
+    "@types/better-sqlite3": "^7.6.13",
+    "@types/cors": "^2.8.19",
+    "@types/express": "^4.17.25",
+    "@types/jsonwebtoken": "^9.0.10",
+    "@types/node": "^20.19.39",
+    "@types/pg": "^8.20.0",
+    "@types/supertest": "^6.0.3",
+    "supertest": "^6.3.4",
+    "tsx": "^4.21.0",
+    "typescript": "^5.9.3",
+    "vitest": "^1.6.1"
+  }
+}

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;

display/middleware/tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "commonjs",
+    "lib": ["ES2022"],
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "declaration": true,
+    "declarationMap": true,
+    "sourceMap": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist", "tests"]
+}

display/middleware/vitest.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    globals: true,
+    environment: 'node',
+    include: ['tests/**/*.test.ts'],
+    testTimeout: 10000,
+  },
+});