fix: shift social preview content left to prevent right-edge clipping (#13)

Logo x: 128→64, text x: 520→456. Balances margins so longer taglines
(e.g. "Schema-driven business configuration") don't get clipped in
LinkedIn/Twitter thumbnails.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: zeevdr