E-Commerce Availability Checker

## Setup Instructions
1. **Define Product List**: Edit the Code node to add your target URLs, CSS selectors for the stock status element, and the text that indicates "In Stock".
2. **HTML Parsing**: This workflow uses a basic HTML Extract node. Ensure your CSS selectors are accurate.
3. **Notifications**: Configure the Slack node with your webhook URL or OAuth token.
4. **Error Handling**: The workflow catches HTTP errors (e.g., 404s) and reports them separately.