Context Arena: Added stealth model "Ox Alpha" (run via @OpenRouter) on 8-needle GDM-MRCRv2! Name will change on reveal. The new stealth model hits 75.3% AUC@128k on high thinking, matching Gemini 3.1 Pro, GPT-5.6 Luna, Muse Spark 1.2, Grok 4.6, and GLM-5.3 (low) while beating…