feat(Radio):
- Redesigned Queue modal, added drag & drop capabilities
- Added stream quality selector, currently offering: AAC @ 128kbps, AAC @ 320kbps & FLAC (lossless)
fix(middleware): Import API_URL from config and remove hardcoded API_URL definition
security(api): Enhance discord image and video caching with improved signature verification and error handling, updated image proxy to include production checks for signing secret
