Add SSM API service

adapter/ssm.go

@@ -0,0 +1,18 @@
+package adapter
+
+import (
+	"net"
+
+	N "github.com/sagernet/sing/common/network"
+)
+
+type ManagedSSMServer interface {
+	Inbound
+	SetTracker(tracker SSMTracker)
+	UpdateUsers(users []string, uPSKs []string) error
+}
+
+type SSMTracker interface {
+	TrackConnection(conn net.Conn, metadata InboundContext) net.Conn
+	TrackPacketConnection(conn N.PacketConn, metadata InboundContext) N.PacketConn
+}