Reads RankInfoEntry.LowerLimitPoint from ranks.csv (via IGlobalsRepository)
for main-tier floors — no hardcoded thresholds. Master (Point=50000) and
Grand Master (MP-based, floor 5000) branch handles the post-Master path.
GetAsync is a read-only snapshot used later by AI-start's SelfInfo.
13 unit tests cover first-win, loss floors (0, Beginner→D, D→D0), win
crossing 50000, MP awards at Master, GM promotion at MP≥5000, GM floor
protecting against Master demotion, format separation, Crossover throw.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
