{
  "id": "03-zero-output",
  "description": "Zero output — Yield is 0 (not null) because cache_read > 0 and input > 0. Velocity is 0. SNR is 0. 10xDEV is null.",
  "input": {
    "telemetry": { "input": 1000, "output": 0, "cache_write": 500, "cache_read": 3000 },
    "source": { "provider": "test", "model": "test", "tool": "test" }
  },
  "expected": {
    "metrics": { "yield": 0, "leverage": 3.0, "velocity": 0, "snr": 0, "dev10x": null },
    "warnings": ["dev10x_undefined: requires all four pillars > 0"]
  }
}