Add convenience helpers and improve documentation

- Add isInProduction() helper for checking status 3 or 4
- Add getErrorSummary() helper for extracting error messages
- Add fetchAllPages() pagination helper for auto-pagination
- Add comprehensive JSDoc to ListResponse interface
- Create ADR-001 documenting decision not to add listAll() method

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/types.ts

@@ -313,12 +313,35 @@ export interface Document {
 }
 
 /**
- * List response wrapper
+ * Response structure for paginated list operations.
+ *
+ * @remarks
+ * The actual data is in the `items` array, not `data` or `results`.
+ *
+ * @example
+ * ```typescript
+ * const response = await client.documents.list();
+ *
+ * // Access the documents array via `items`
+ * for (const doc of response.items) {
+ *   console.log(doc.filename, doc.status.text);
+ * }
+ *
+ * // Pagination information
+ * console.log(`Showing ${response.items.length} of ${response.total} documents`);
+ *
+ * // Check if more pages exist
+ * const hasMore = response.offset + response.items.length < response.total;
+ * ```
  */
 export interface ListResponse<T> {
+  /** Array of items returned by the query */
   items: T[];
+  /** Total number of items matching the query (across all pages) */
   total: number;
+  /** Maximum number of items per page */
   limit: number;
+  /** Number of items skipped (for pagination) */
   offset: number;
 }