fix: диагностика 502, /health и unit systemd для Caddy

Co-authored-by: Cursor <cursoragent@cursor.com>

src/server.js

@@ -7,6 +7,7 @@ require('./db');
 require('./seed');
 
 const { loadUser } = require('./middleware/auth');
+const healthRoutes = require('./routes/health');
 const shopRoutes = require('./routes/shop');
 const authRoutes = require('./routes/auth');
 
@@ -22,6 +23,8 @@ if (process.env.TRUST_PROXY === '1' || isProduction) {
 app.set('view engine', 'ejs');
 app.set('views', path.join(__dirname, 'views'));
 
+app.use(healthRoutes);
+
 app.use(express.static(path.join(__dirname, 'public')));
 app.use(express.urlencoded({ extended: true }));
 
@@ -62,6 +65,11 @@ app.use((err, req, res, _next) => {
   });
 });
 
-app.listen(PORT, HOST, () => {
+const server = app.listen(PORT, HOST, () => {
   console.log(`Магазин: http://${HOST}:${PORT}`);
 });
+
+server.on('error', (err) => {
+  console.error('Не удалось запустить сервер:', err.message);
+  process.exit(1);
+});