Disable synchronize and fix DB manually

backend/src/config/database.config.ts

@@ -24,8 +24,8 @@ export const databaseConfig: TypeOrmModuleAsyncOptions = {
     // Entity auto-discovery
     autoLoadEntities: true,
 
-    // Temporarily set to true to ensure tables are created (will switch back to migrations later)
+    // NEVER synchronize — use migrations or manual SQL only
-    synchronize: true,
+    synchronize: false,
 
     // SSL is not required for internal Docker network
     ssl: false,