feat: add remote NodeService client backed by the HTTP API

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

service/config.go

@@ -19,5 +19,7 @@ type Config interface {
 	DeleteAlias(name string) error
 	ListAliases() ([]*Alias, error)
 	GetServerConfig() ServerConfig
+	// GetRemoteConfig returns the remote server address and whether remote mode is enabled.
+	GetRemoteConfig() (ServerConfig, bool)
 	Save() error
 }