- Add sharp@0.34.5 dependency for server-side image processing
- Create /api/seo-image endpoint to resize og:images to 1200x630 JPEG
- Replace toOptimizedSeoImageUrl with toSeoImageUrl routing through custom endpoint
- Implement host validation to prevent open proxy abuse (allow vcci-hcm.org.vn, vccihcm.vn)
- Add automatic fallback to /thumbnail.png when source image fails
- Set aggressive caching headers (max-age=86400, s-maxage=2592000)
- Support both absolute