refac: hardening pass with multiple overhauls

api/handlers/user/inviteHandler.go

@@ -19,7 +19,7 @@ type InviteHandler struct {
 }
 
 type CreateInviteRequest struct {
-	Email string `json:"email" validate:"required,email"`
+	Email string `json:"email" validate:"required,inviteemail"`
 }
 
 type inviteResponse struct {