Set File Upload fields as mandatory

Set File Upload fields as mandatory

Currently the CRM for some reason lacks the ability to set a file upload field as mandatory 

So we have an issue 

We have a requirement that before a Deal stage is set as Deal is Won the member needs to upload a file 

Now for some weird reason in Zoho I cannot set a file upload as mandatory via layout rules or in the module layout

Only workaround I found is client script

So I tried Client Script and using Client Script in the Edit Page I can set a File upload as Mandatory
but not in Detail Page 
So I thought of making Stage read only in Detail Page 
and that's not possible as well 

It's really frustrating when simple things like these need workarounds