Add system for managing and scheduling data backups

Introduce a new backup management feature with automated scheduling, manual backups, and a dedicated interface for viewing backup status and details. This includes integrating `node-cron` for scheduling, updating the database schema to store backup information, and creating new routes and components for the backup manager.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: 7c468936-2a88-4686-ac0a-84921a45222d
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/7c468936-2a88-4686-ac0a-84921a45222d/9xfbVBU

client/src/components/Layout.tsx

@@ -138,7 +138,7 @@ export default function Layout({ children }: LayoutProps) {
                         <div className="flex items-center gap-2">
                           <div 
                             className="w-3 h-3" 
-                            style={{ backgroundColor: store.color }}
+                            style={{ backgroundColor: store.color || '#gray-400' }}
                           />
                           <span>{store.name}</span>
                         </div>