Scrape Books from URL with Dumpling AI, Clean HTML, Save to Sheets, Email as CSV

### 🔁 Trigger to Raw Book HTML

1. **Google Sheets Trigger**  
   Watches a sheet for new row entries. Once a new URL is added, the workflow starts.

2. **Fetch Website Content (Dumpling AI)**  
   Makes an HTTP POST request to Dumpling AI to scrape and return the full HTML of the target URL.

3. **Extract All Books**  
   Uses CSS selectors to isolate the list items (`li.row > li`) containing book entries.

4. **Split Out Node**  
   Breaks the array of book HTML blocks into individual items, so each book can be processed separately in the next steps.