Compile TSQL stored procedures into assembly
No, there is no way to do this. And there is not much purpose in doing so anyway as you can easily decompile Assemblies with tools such as ILSpy.

The two ways to protect your intellectual property are:


Proper license agreement. Consult with a lawyer to see what is best for you. There are many options and laws vary by state / region / country / etc so advice you get online might not be correct for you.
Innovation. Even if you protect the code from being seen, it can still be reversed engineered by observation / testing. Keep evolving and improving.
Yes, this is now more than 2, but this one isn't exactly protecting the intellectual property, BUT... Support: provide great support and that will help in some cases. Provide good, thorough documentation and fix things as quickly as possible when someone identifies a bug. This is harder to duplicate than code ;-).