fix: increase DB pool size and fix connection leak in permissions route

- connectionLimit 10 -> 50, queueLimit 0 -> 100 to prevent pool exhaustion
- Add missing db.release() in GET /permissions/:id finally block

backend/managerRoutes.js

@@ -826,6 +826,8 @@ export default function () {
       res
         .status(500)
         .json({ message: 'Database error fetching manager permissions.', details: error.message })
+    } finally {
+      db.release()
     }
   })
 

backend/pool.js

@@ -13,8 +13,8 @@ const db = mysql.createPool({
   database: process.env.DB_NAME,
   port: process.env.DB_PORT,
   waitForConnections: true,
-  connectionLimit: 10,
-  queueLimit: 0,
+  connectionLimit: 50,
+  queueLimit: 100,
   // timezone: '+08:00',
   dateStrings: true,
 });

backend/test.js

@@ -0,0 +1,22 @@
+import { getConnection } from './pool.js'
+// import mysql from 'mysql2/promise'
+//
+//
+//
+// export const db = mysql.createPool({
+//   host: '47.254.195.2',
+//   user: 'nilai_clock_indo',
+//   password: '5jHy8ZsfeEjPAhYS',
+//   database: 'nilai_clock_indo',
+//   port: 3306,
+//   waitForConnections: true,
+//   connectionLimit: 10,
+//   queueLimit: 0,
+//   dateStrings: true,
+//   // 不在这里设置timezone，因为我们用查询设置
+// });
+
+const conn = await getConnection()
+
+const [rows] = await conn.execute('select * from clock_records where id= 6654');
+console.log(rows);