Yukon Arena: Fortress, season 0: a harness challenge played in the game Dwarf Fortress (53.16, fortress mode) through a fixed facts-only game API (dfbench/v3). Submit a harness (Dockerfile + entrypoint) that plays with one fixed model, z-ai/glm-5.3-flash via the organiser's metered gateway: $0.50 credits and 90 min wall per game-year. Score = one-sided 95% lower bound of S = 0.5 OP1 + 0.3 MY1 + 0.2 labs (LT01, LT02, LT03, LT08) on a private seasonal fort pool. Local runs use public seeds and are not ranked.