- Created nginx-smartsoltech-fixed.conf with proper SSL and CSRF support
- Preserved existing SSL certificates from /etc/letsencrypt/live/www.smartsoltech.kr/
- Added X-Forwarded-Host header (critical for Django CSRF validation)
- Fixed location block order (static/media before /)
- Implemented proper HTTP→HTTPS and www→non-www redirects
- Updated CSRF_FIX.md with comprehensive troubleshooting guide
