Bokeh plot legend labels are not descriptive (c1, c2, etc.)

[ken-lauer]

For example, when plotting orbit, beta, and dispersion with the bokeh backend:

See that the legend labels are not descriptive. The label text is readily available (and working in the matplotlib backend).
The underlying issue is that bokeh itself does not support LaTeX (MathJAX) strings in legend labels currently (as of 1/2025 at least).

Resolving this may include:

1. Best-effort converting the pgplot-format axis labels into standard unicode (short term fix)
2. Waiting until Bokeh supports LaTeX (long/unknown term fix)