feat(listing): Add memory-efficient listing APIs: async generator, RxJS observable, and cursor pagination; export ListCursor and Minimatch; add minimatch dependency; bump to 4.2.0

ts/classes.listcursor.ts

@@ -0,0 +1,89 @@
+// classes.listcursor.ts
+
+import * as plugins from './plugins.js';
+import type { Bucket } from './classes.bucket.js';
+
+export interface IListCursorOptions {
+  pageSize?: number;
+}
+
+export interface IListCursorResult {
+  keys: string[];
+  done: boolean;
+}
+
+/**
+ * ListCursor provides explicit pagination control for listing objects in a bucket.
+ * Useful for UI pagination, resumable operations, and manual batch processing.
+ */
+export class ListCursor {
+  private continuationToken?: string;
+  private exhausted = false;
+  private pageSize: number;
+
+  constructor(
+    private bucket: Bucket,
+    private prefix: string,
+    options: IListCursorOptions = {}
+  ) {
+    this.pageSize = options.pageSize || 1000;
+  }
+
+  /**
+   * Fetch the next page of object keys
+   * @returns Object with keys array and done flag
+   */
+  public async next(): Promise<IListCursorResult> {
+    if (this.exhausted) {
+      return { keys: [], done: true };
+    }
+
+    const command = new plugins.s3.ListObjectsV2Command({
+      Bucket: this.bucket.name,
+      Prefix: this.prefix,
+      MaxKeys: this.pageSize,
+      ContinuationToken: this.continuationToken,
+    });
+
+    const response = await this.bucket.smartbucketRef.s3Client.send(command);
+
+    const keys = (response.Contents || [])
+      .map((obj) => obj.Key)
+      .filter((key): key is string => !!key);
+
+    this.continuationToken = response.NextContinuationToken;
+    this.exhausted = !this.continuationToken;
+
+    return { keys, done: this.exhausted };
+  }
+
+  /**
+   * Check if there are more pages to fetch
+   */
+  public hasMore(): boolean {
+    return !this.exhausted;
+  }
+
+  /**
+   * Reset the cursor to start from the beginning
+   */
+  public reset(): void {
+    this.continuationToken = undefined;
+    this.exhausted = false;
+  }
+
+  /**
+   * Get the current continuation token (for saving/restoring state)
+   */
+  public getToken(): string | undefined {
+    return this.continuationToken;
+  }
+
+  /**
+   * Set the continuation token (for resuming from a saved state)
+   */
+  public setToken(token: string | undefined): void {
+    this.continuationToken = token;
+    this.exhausted = !token;
+  }
+}