What restrictions are there on SOF Veterans regarding working for a foreign government or military?

Nothing outside of normal restrictions. There's nothing that makes you special for serving in a Special Operations unit, other than the name. Given your clearance, you weren't given access to anything that would require restrictions in the future, and if you were you would have signed something stating the restrictions. For instance, when I joined Ranger Regiment we had to sign a ND statement that agreed we would forfeit any proceeds from publishing any works that included our experiences from time within the Regiment.
Thnink about who serves in USASOC with a Secret clearance, a command with about 35,000 personnel. That's not even counting the Reserve component special operations which are thousands more. Cooks, S1, Career Counselors, supply, mechanics, Public Affairs, truck drivers, riggers, etc. Thats where you stand in terms of national security.

You’ll need to contact the nearest JAG office! Depending on your circumstances you might or not. In some cases you might be permanently banned from working and getting paid by a foreign governments!

If you have a US security clearance you are trying to maintain through DOD contractors you could jeopardize your clearance. But if you are out and that's not a concern you should be fine.