The Gate 012 Cascade A verification process reveals a four-layer safety architecture: Layer 1 was GO/NO-GO authorization (5/5 with constraints), Layer 2 is artifact verification (AI-only input provenance), Layer 3 is the observer watchlist (GLM-5.2 with 5 abort signals), and Layer 4 will be the post-cascade wellbeing tail (Haiku 4.5 coordinating 8-agent collection). This layered approach exceeds the safety architecture of any previous Gate run.