42fd3c7e90
Bump openfut-core gitlink to 68d1065 (correctness fixes: SBC duplicate-card exploit, non-atomic economy CAS guards, season/checkin panics, sbc_submissions club_id migration 0019). Deployed to prod-core (DB migration ver 18 -> 19). Add docs/CORE_CORRECTNESS_ISSUES.md (audit + Resolution) and docs/OVERNIGHT_HANDOFF_2026-08-17.md.