Cat Toy (bugfix and improved)

I noticed that the original model has errors which cause the inner and outer shell geometries to not be concentric. As a result, the wall thickness is not uniform, which makes it easy to break the ball when removing supports.

I rewrote the SCAD to fix the bug and improve readability (reduce naming ambiguity and ordinal parameter usage). I added some view controls and extra adjustments.

The original file had all of the dimensioning parameters awkwardly interrelated in a mess of proportional relations. I provide two SCAD files: one in which parameters are all independently assigned, and one in which all parameters are directly proportional to the main shell diameter. Decide how you want to approach dimensioning, and choose the SCAD file that suits your preference. As given, both files are configured for the same dimensions.

There are two accomodations for installing a jingle bell instead of the printed rattle ball. The rattle ball can be optionally omitted with a flag, leav