feat(smarts3-server): Introduce native custom S3 server implementation (Smarts3Server) with routing, middleware, context, filesystem store, controllers and XML utilities; add SmartXml and AWS SDK test; keep optional legacy s3rver backend.

ts/utils/xml.utils.ts

@@ -0,0 +1,39 @@
+import * as plugins from '../plugins.js';
+
+// Create a singleton instance of SmartXml
+const smartXmlInstance = new plugins.SmartXml();
+
+/**
+ * Parse XML string to JavaScript object
+ */
+export function parseXml(xmlString: string): any {
+  return smartXmlInstance.parseXmlToObject(xmlString);
+}
+
+/**
+ * Convert JavaScript object to XML string with XML declaration
+ */
+export function createXml(obj: any, options: { format?: boolean } = {}): string {
+  const xml = smartXmlInstance.createXmlFromObject(obj);
+
+  // Ensure XML declaration is present
+  if (!xml.startsWith('<?xml')) {
+    return `<?xml version="1.0" encoding="UTF-8"?>\n${xml}`;
+  }
+
+  return xml;
+}
+
+/**
+ * Helper to create S3-compatible XML responses with proper namespace
+ */
+export function createS3Xml(rootElement: string, content: any, namespace = 'http://s3.amazonaws.com/doc/2006-03-01/'): string {
+  const obj: any = {
+    [rootElement]: {
+      '@_xmlns': namespace,
+      ...content,
+    },
+  };
+
+  return createXml(obj, { format: true });
+}