The constant was supposed to represent 30 game-minutes but the formula
was wrong (30 × 10 tps × 60s = 1800). Correct derivation: 30 minutes ×
TICKS_PER_GAME_MINUTE (10) = 300. Now uses the canonical constant
directly. Also fixes stale assertion message in integration test.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>