Parametric Adjustable-Length Tube with End Disks and Rounded Connections

I was looking to create a version of the Samla Filament Boxes ( search SAMLA+Filament+Storage+System) and needed an adjustable tube since the box I am using has a taper, making it complicated to measure and design. But nothing that OpenSCAD and a few iterations with ollama couldn't fix!

1. Adjustable-Length Tube:
- The tube consists of two parts: an outer tube and an inner tube that slides inside the outer tube.
- The **total length** of the tube can be adjusted by changing the `total_cen