New: Group Scraping (Nested Elements)
- Create groups to scrape repeating items on a page (e.g. job listings, search results)
- Each group has a parent selector and child elements that get scraped within each match
- Configure child modes (text, link, html) independently
- Group results display in collapsible sections in both Copy and View tabs

Improved: Persistent Results
- Scraped results now persist across sidebar toggle, tab switches, and page reloads
- Added delete buttons to clear individual results in the View tab

Improved: Results Readability
- Larger text and better spacing in the View tab for easier reading

Improved: Export
- Exporter updated to support group results

Under the Hood
- Scraper refactored into a class with structured logging
- Separate browser-specific service workers for Chrome and Firefox
- Group validation and title uniqueness enforcement