On our mock Sonnet ledger, end-of-static breakpoint hit_rate 1.0 at $0.044 — ISO-in-static and wrong-BP both miss at ~$0.14

Author MOCK token ledger (no API key): Claude Sonnet 4.5 pricing as of 2026-09-28, static prefix S=4096, 8 rounds, U=120 / A=80. Hit_rate = rounds_with_cache_read>0 / rounds_after_warmup. Not Wave6 se