Prototype: Show grade in track monitor proto#8

Draft

rwf-rr wants to merge 3 commits intomasterfrom

show-grade-in-track-monitor-proto

Commits on Aug 22, 2025

First part of prototype to show grade ahead in track monitor.
rwf-rr
committed

Commits on Sep 6, 2025

Interim: combining grades (grade info objects), which I rejected.
rwf-rr
committed

Commits on Sep 16, 2025

Partial changes to use unidirectional gradeposts.
rwf-rr
committed