Now that a Wildcard winner's destination depends on both games, guarding
only the slot about to be written is not enough. Correcting a recorded
result placed the new winner in the other Elimination Final and left the
beaten team alive in the one it had been written to, and a bracket already
advanced under the old fixed crossover ended up with one team in both
Elimination Finals once the second result came in — the second write hit
"already filled", which every caller swallows.
Each result now reconciles both slots against the resolved pairings:
a Wildcard team sitting in the wrong slot is vacated, the right ones are
written, and a slot held by anyone outside the Wildcard Round still raises
"already filled" rather than being taken. Clearing and filling share one
transaction, so a half-applied re-seed cannot leave a team in both games,
and pairings that are already correct do no writes at all.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VDbHrCce1UhahbkwKkc7hK
273735e572