Initial commit: teaching institution management API.

Express/MongoDB backend with JWT auth, RBAC, S3 uploads, notifications, and scheduled jobs.

config/db.js

@@ -0,0 +1,27 @@
+// /config/db.js
+
+const mongoose = require('mongoose');
+const config = require('./config');
+const logger = require('../utils/logger');
+
+const connectDB = async () => {
+  try {
+    const conn = await mongoose.connect(config.MONGO_URI, {
+      autoIndex: true
+    });
+    logger.info(`MongoDB Connected: ${conn.connection.host}`);
+  } catch (error) {
+    logger.error(`Database connection error: ${error.message}`);
+    process.exit(1);
+  }
+};
+
+mongoose.connection.on('disconnected', () => {
+  logger.warn('MongoDB disconnected. Attempting to reconnect...');
+});
+
+mongoose.connection.on('error', (err) => {
+  logger.error(`MongoDB connection error: ${err.message}`);
+});
+
+module.exports = connectDB;