Website restoration: Node.js backend, restored design, GitHub sync disabled

- Replaced broken .NET backend with Node.js/Express
- Restored original website design with purple gradient hero
- Updated homepage and shop pages with Bootstrap 5 responsive design
- Disabled GitHub remote sync - all code now stored locally only
- Created backup scripts and documentation
- All changes saved on Ubuntu server at /var/www/SkyArtShop

backend/node_modules/postgres-interval/index.d.ts

@@ -0,0 +1,20 @@
+declare namespace PostgresInterval {
+  export interface IPostgresInterval {
+    years?: number;
+    months?: number;
+    days?: number;
+    hours?: number;
+    minutes?: number;
+    seconds?: number;
+    milliseconds?: number;
+
+    toPostgres(): string;
+
+    toISO(): string;
+    toISOString(): string;
+  }
+}
+
+declare function PostgresInterval(raw: string): PostgresInterval.IPostgresInterval;
+
+export = PostgresInterval;