chore: move the go code into a subfolder

apps/api/internal/user/model/otp.go

@@ -0,0 +1,24 @@
+package model
+
+type MFAState int32
+
+const (
+	MFAStateUnspecified MFAState = iota
+	MFAStateNotReady
+	MFAStateReady
+)
+
+type MultiFactor struct {
+	Type      MFAType
+	State     MFAState
+	Attribute string
+	ID        string
+}
+
+type MFAType int32
+
+const (
+	MFATypeUnspecified MFAType = iota
+	MFATypeOTP
+	MFATypeU2F
+)