mirage 是做什麼的？
Use when you need a NEW or optimized MPK CUDA kernel (a per-task .cuh under include/mirage/persistent_kernel/tasks/) that must PROVABLY beat a target WITHOUT the kernel-optimizer cheating its own correctness test. This is the frozen-gate Ferret system — a 3-agent orchestration (dispatcher → independent test-writer → optimizer) that makes "the optimizer ships a simplified-math kernel and self-reports a passing test" structurally impossible. Triggers — phrasings like "dispatch ferret to optimize