Simulates the 20-team Little League World Series: pool play round-robin
(5 teams/pool, top 2 advance) → 4-team double-elimination per side
(US and International) → consolation game → World Series final.
Uses championship futures odds as the sole win-probability signal.
Pool assignments are auto-detected from externalId: bare "US"/"Intl"
randomizes pools each simulation (pre-draw mode); "US:A"/"Intl:B" etc.
uses fixed assignments (post-draw mode). Sides can differ.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
