690f8c5c38
- Implemented "sidecar" thumbnail logic: imports video thumbnails from Google Photos as hidden Drive files to display immediately while videos process. - Updated MediaService to serve sidecar thumbnails via server-side Base64 encoding, bypassing CORS restrictions. - Implemented lifecycle management: detects video processing completion to automatically cleanup sidecar files and fallback to native Drive thumbnails. - Enhanced Media Manager UI: added processing warning banner and refined processing tile styling (centered, lighter overlay). - Upgraded Drive API to v3 and improved file creation robustness with Advanced API fallbacks.