feat: support interactive SSH port forwarding (#67)

internal/core/ports/services.go

@@ -27,5 +27,9 @@ type ServerService interface {
 	DeleteServer(server domain.Server) error
 	SetPinned(alias string, pinned bool) error
 	SSH(alias string) error
+	SSHWithArgs(alias string, extraArgs []string) error
+	StartForward(alias string, extraArgs []string) (int, error)
+	StopForwarding(alias string) error
+	IsForwarding(alias string) bool
 	Ping(server domain.Server) (bool, time.Duration, error)
 }