refactor: move http api to a new transport layer

internal/types/node.go

@@ -2,13 +2,15 @@ package types
 
 import "fmt"
 
+type Nodes map[string]Node
+
 // TODO: consider moving this type back to registry
 type Node struct {
 	Hostname string `json:"hostname"`
 	Address  string `json:"address"`
 	Port     int    `json:"port"`
 	Roles    []Role `json:"roles"`
-	Endpoint string `json:"endpoint"`
+	Endpoint string `json:"endpoint"` // TODO: make endpoint into a separate type
 }
 
 func NewNode(