Tension smoothing

The image below shows a comparison between the raw data, using the built-in `unwrap` function and a custom implementation using a window of 5 previous elements to decide whether it is actually a phase shift.

All values above 400 (arbitrary) are then assigned `NaN`. Then we run a smoothing filter: gaussian with 8 elements

About 1 degree or so is lost from smoothing.

No source file or test is identified. Start by locating the code that calls the built-in unwrap, applies the five-element custom comparison, assigns values above 400 to NaN, and runs the eight-element Gaussian filter. Done should include an agreed acceptable smoothing loss and expected output.

Written by the indexing model from the issue text.