feat: каркас Express + pg, health check

src/db.js

@@ -0,0 +1,24 @@
+const { Pool } = require('pg');
+require('dotenv').config();
+
+const pool = new Pool({
+  host: process.env.DB_HOST,
+  port: process.env.DB_PORT || 5432,
+  database: process.env.DB_NAME || 'postgres',
+  user: process.env.DB_USER,
+  password: process.env.DB_PASS,
+  ssl: process.env.DB_SSLMODE === 'require' ? { rejectUnauthorized: false } : false,
+  max: 10,
+  idleTimeoutMillis: 30000,
+});
+
+pool.on('error', (err) => {
+  console.error('DB pool error:', err.message);
+});
+
+async function checkConnection() {
+  const { rows } = await pool.query('SELECT 1 AS ok');
+  return rows[0].ok === 1;
+}
+
+module.exports = { pool, checkConnection };