添加Health健康检查端点

server/db.js

@@ -18,9 +18,20 @@ function initPool() {
   });
 }
 
+async function checkHealth() {
+  try {
+    if (!pool) return { status: 'down', error: 'Database pool not initialized' };
+    await pool.query('SELECT 1');
+    return { status: 'up' };
+  } catch (err) {
+    return { status: 'down', error: err.message };
+  }
+}
+
 initPool();
 
 module.exports = {
   query: (...args) => pool.query(...args),
-  initPool
+  initPool,
+  checkHealth
 };