- Create migration for global settings table and add google_ads_customer_id and google_ads_start_date columns to clients table.
- Add migration to include product_url column in products_data table.
- Insert demo data for campaigns, products, and their history for client 'pomysloweprezenty.pl'.
- Implement client management interface with modals for adding and editing clients, including Google Ads Customer ID and data retrieval start date.
