fix(supervisor): stabilize control JSON contract

runtime/supervisor/supervisor.go

@@ -18,24 +18,24 @@ const (
 )
 
 type Release struct {
-	ID            string
-	Version       string
-	State         ReleaseState
-	LastKnownGood bool
+	ID            string       `json:"id"`
+	Version       string       `json:"version"`
+	State         ReleaseState `json:"state"`
+	LastKnownGood bool         `json:"last_known_good"`
 }
 type Observation struct {
-	ReleaseID            string
-	Ready                bool
-	Reason               string
-	ObservedAtUnixMillis int64
+	ReleaseID            string `json:"release_id"`
+	Ready                bool   `json:"ready"`
+	Reason               string `json:"reason"`
+	ObservedAtUnixMillis int64  `json:"observed_at_unix_millis"`
 }
 type Lifeboat struct {
-	Current           Release
-	LastKnownGood     Release
-	Observations      []Observation
-	TrafficMode       TrafficMode
-	StableUpstream    string
-	CandidateUpstream string
+	Current           Release       `json:"current"`
+	LastKnownGood     Release       `json:"last_known_good"`
+	Observations      []Observation `json:"observations"`
+	TrafficMode       TrafficMode   `json:"traffic_mode"`
+	StableUpstream    string        `json:"stable_upstream"`
+	CandidateUpstream string        `json:"candidate_upstream"`
 }
 
 func (l *Lifeboat) Start(candidate Release) bool {