rev hang aka upshift rev match

The car has a light flywheel, so sometimes the revs drop too much during a shift and you get a jerky shift. We can slow the rev drop if we detect you're doing this (clutch down, at speed, etc) and hold revs near the next gear.


The issue names no files, tests, or entry points. Start by locating the firmware's clutch, shifting, and engine-speed control logic, then determine how a shift can be recognized and how long revs should be held near the next gear; done means the behavior is implemented and verified without causing jerky shifts.

Written by the indexing model from the issue text.