Health
Is the server up, and is the pipeline ticking.
/
Root banner: the server is up and answering.
/api/fusion/health
Every field is computable **without ground truth**, so this is as valid against
/api/health
Lightweight liveness probe: whether the fusion pipeline has produced a recent track.
/api/metrics
Liveness plus the degraded flag the console reads.
/health
Root-scope health check: the server is up and answering.