A top-level const in api/game.php was declared below the dispatch, so it was
not defined yet when finishing a bot game called chessBotTooShort(): every
bot game ended in "Undefined constant", was never closed and never paid.
Declared above the dispatch now.

Also the applied follow-up migration: account deletion no longer fails for
code creators and reviewers, legacy group codes are unique by canonical form,
tournament codes register through tournament_register (no drafts, window and
fee honoured), the table keeps its game order, the test ad is paused.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>