[
  {
    "description": "Standard beat frame during execute phase",
    "message": {
      "type": "backbeat.beatframe.v1",
      "cluster_id": "chorus-prod",
      "beat_index": 1337,
      "downbeat": false,
      "phase": "execute",
      "hlc": "7ffd:0001:abcd",
      "deadline_at": "2025-09-05T12:30:00Z",
      "tempo_bpm": 2.0,
      "window_id": "7e9b0e6c4c9a4e59b7f2d9a3c1b2e4d5"
    }
  },
  {
    "description": "Downbeat starting new bar in plan phase",
    "message": {
      "type": "backbeat.beatframe.v1",
      "cluster_id": "dev-cluster",
      "beat_index": 0,
      "downbeat": true,
      "phase": "plan",
      "hlc": "0001:0000:cafe",
      "deadline_at": "2025-09-05T12:00:30Z",
      "tempo_bpm": 4.0,
      "window_id": "a1b2c3d4e5f6789012345678901234ab"
    }
  },
  {
    "description": "High-frequency beat with metadata",
    "message": {
      "type": "backbeat.beatframe.v1",
      "cluster_id": "fast-cluster",
      "beat_index": 999999,
      "downbeat": false,
      "phase": "review",
      "hlc": "abcd:ef01:2345",
      "deadline_at": "2025-09-05T12:00:07.5Z",
      "tempo_bpm": 8.0,
      "window_id": "fedcba9876543210fedcba9876543210",
      "metadata": {
        "pulse_version": "1.2.3",
        "cluster_health": "healthy",
        "expected_agents": 150
      }
    }
  },
  {
    "description": "Low-frequency beat (1 BPM = 60 second beats)",
    "message": {
      "type": "backbeat.beatframe.v1",
      "cluster_id": "slow-batch",
      "beat_index": 42,
      "downbeat": true,
      "phase": "plan",
      "hlc": "FFFF:FFFF:FFFF",
      "deadline_at": "2025-09-05T13:00:00Z",
      "tempo_bpm": 1.0,
      "window_id": "0123456789abcdef0123456789abcdef",
      "metadata": {
        "pulse_version": "2.0.0",
        "cluster_health": "degraded",
        "expected_agents": 5
      }
    }
  },
  {
    "description": "Minimal valid beat frame (no optional fields)",
    "message": {
      "type": "backbeat.beatframe.v1",
      "cluster_id": "minimal",
      "beat_index": 1,
      "downbeat": false,
      "phase": "execute",
      "hlc": "0000:0001:0002",
      "deadline_at": "2025-09-05T12:01:00Z",
      "tempo_bpm": 2.0,
      "window_id": "1234567890abcdef1234567890abcdef"
    }
  }
]