Extends pose angle tracking with knee bend (hip-knee-ankle), then uses
it alongside the existing elbow/shoulder angles in a new
PoseStageAdvisor to give a short live cue for whichever step of the
approach is in progress: push-away on step 2, downswing on step 3,
backswing on step 4, and knee-bend/arm-extension on the final step.
Thresholds are starting defaults, not measured coaching data, and are
expected to be retuned against real approach footage.
Also fixes a layout bug found while testing this live: the new
feedback text was chained via ConstraintLayout's toBottomOf to the
step banner above it, so whenever that banner was hidden (GONE) the
feedback text rendered at its collapsed zero-height position instead
of staying put, landing on top of the recording indicator. Both now
sit in a plain vertical LinearLayout, which collapses GONE children
correctly.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
