Gaze magnitude now comes from the angle to the pointer rather than a
linear distance ramp:
gain = distance / hypot(distance, depth)
That is the projection of an eyeball rotating to face a target `depth`
away, so it saturates. Once the pointer passes the knee the eyes hold
near-full deflection and keep pointing straight at it, which is what
reads as being looked at. Measured angle error against the true cursor
direction is 0 degrees.
Default travel rises from 9 to 30 SVG units. The eye group is clipped to
the head silhouette and the outer eye edge sits 48 units from it, so 30
stays clear while the slider can explore up to the clip. At the shipping
46px render this moves the pupils 4.5 screen px instead of 1.4.
Extract the tracker into davebotGaze.ts and add davebot-gaze.html, a
tuning lab with live controls for travel, depth, smoothing, convergence
and lean. Settings persist, so the header reads whatever the lab last
saved. Sliders are generated from the engine's own limits and read back
its clamped values, so the panel cannot display a number the tracker is
not using.
