The main idea is the following:

• use bullet collision checker to get infos of collision closest points -> distance + direction can be extracted for each contact
• for each collision below a certain distance apply a scaling only on the component that would cause collisions
• for the moment rotation induced collisions are avoided by introducing a translation (this can have some disadvantage see comment in the code)

As a result what you will get is that even if you push the robot into a surface but at the same time you try to slide on it only the pushing velocity component will be scaled.

Current (known) limitations:

• allowed collision matrix seems to be not considered properly
• in some (panda) robot configuration the collision checker is missing collisions