feat(platform): expose source slots in vehicle service

vehicle-data-platform/apps/api/internal/platform/service.go

@@ -68,6 +68,23 @@ func missingCanonicalProtocols(protocols []string) []string {
 	return missing
 }
 
+func buildVehicleCoverageSourceStatus(protocols []string, onlineProtocols []string, lastSeen string) []VehicleSourceStatus {
+	statuses := make([]VehicleSourceStatus, 0, len(protocols))
+	for _, protocol := range protocols {
+		protocol = strings.TrimSpace(protocol)
+		if protocol == "" {
+			continue
+		}
+		statuses = append(statuses, VehicleSourceStatus{
+			Protocol:    protocol,
+			Online:      containsString(onlineProtocols, protocol),
+			LastSeen:    lastSeen,
+			HasRealtime: true,
+		})
+	}
+	return completeVehicleSourceStatus(statuses, "")
+}
+
 func NewService(store Store) *Service {
 	return &Service{store: store}
 }