Brand Logo Finder download fix
Fixed logo downloads failing with "Logo not available" and "Invalid domain" errors on the Brand Logo Finder tool.
- Switched from an incorrect CDN URL format to the Brandfetch Brand API for retrieving actual SVG and PNG logo file URLs.
- Added graceful fallback: serves PNG when SVG is not available for a brand, with correct filename extension.
- Downloads are now cached server-side for 1 hour to minimize API quota usage.