refreshVScaleMenu() was unconditionally removing the cal-invalid class
from all three calibration inputs, which silently cleared the red-border
error indicator on a field the user was editing whenever a hub
calibration broadcast arrived. Apply the same focused-element guard
already used for .value writes so a rejected value's error styling
persists until the user corrects it.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Adds the Cal row (Scale / Offset / Unit / Reset) to #vscale-menu, its
CSS, and the refreshVScaleMenu() / commitCal() logic that wires it to
calTable and the hub via setCalibrationWS.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
