I made this before (but lost it)
All the clientside part is, is a clientCmd that aims at a certain position, and then the serverside addon tells the client to look at the position, repeatedly inside a looping scheduled function
This is a perfectly valid request, and has many valid uses.
For example, filming. You can smoothly follow a player/any object with this.
You could tie the aiming to a single tool if you wanted, so it wouldn't be able to be used with a weapon