fix: import issue

apps/api/src/app/endpoints/ai/ai.service.ts

@@ -10,7 +10,9 @@ import type { AiPromptMode } from '@ghostfolio/common/types';
 import { Injectable } from '@nestjs/common';
 import { createOpenRouter } from '@openrouter/ai-sdk-provider';
 import { generateText } from 'ai';
-import tablemark, { ColumnDescriptor } from 'tablemark';
+import { ColumnDescriptor } from 'tablemark';
+
+const tablemark = require('tablemark').default;
 
 // Column name constants for holdings table
 const HOLDINGS_TABLE_COLUMNS = {