fixed login error

backend/src/server.js

@@ -126,7 +126,10 @@ const startServer = async () => {
       process.env.NODE_ENV !== 'production' || autoSync || isSqlite;
     if (shouldSync) {
       console.log('🔄 Syncing database models...');
-      const alter = process.env.NODE_ENV !== 'production';
+      // Never use alter on SQLite: Sequelize copies via *_backup tables with NOT NULL timestamps;
+      // migrated rows with null created_at/updated_at → INSERT fails → crash loop (PM2 502).
+      const alter =
+        process.env.NODE_ENV !== 'production' && sequelize.getDialect() !== 'sqlite';
       await sequelize.sync({ alter });
       console.log('✅ Database models synchronized');
     } else {
@@ -147,12 +150,15 @@ const startServer = async () => {
       console.log(`🔔 Notifications: http://localhost:${PORT}/api/notifications`);
     });
   } catch (error) {
-    console.error('❌ Database connection failed:', error.message);
-    console.log('💡 Please ensure PostgreSQL is running and the database credentials are correct.');
-    console.log('💡 You can also try:');
-    console.log('   1. Check if PostgreSQL service is running');
-    console.log('   2. Verify database credentials in .env file');
-    console.log('   3. Create the database: CREATE DATABASE luckychit;');
+    const d = sequelize.getDialect();
+    console.error('❌ Server startup failed:', error.message);
+    if (error.errors) console.error(error.errors.map((e) => e.message).join('; '));
+    if (d === 'sqlite') {
+      console.log('💡 SQLite: check SQLITE_STORAGE path, file permissions, and avoid sync alter with bad data.');
+    } else {
+      console.log('💡 Ensure the database is running and credentials in .env are correct.');
+      console.log('💡 Create the DB if needed: CREATE DATABASE luckychit;');
+    }
     process.exit(1);
   }
 };