ScatterTrace overrides every public Movable entry point — moveOnce,
moveToExtreme, moveToIndex, isMovable — and drives navigation itself, using
this class purely as a position store (row / col / isInitialEntry) exposed
through the AbstractPlot accessors. The navigation methods below are required
by the Movable interface but are never invoked for scatter; they are inert
stubs so that the previously duplicated (and already-diverged) plane
navigation logic cannot be "fixed" here with no effect on runtime behavior.
Minimal row/col cursor store for ScatterTrace.
ScatterTrace overrides every public Movable entry point — moveOnce, moveToExtreme, moveToIndex, isMovable — and drives navigation itself, using this class purely as a position store (row / col / isInitialEntry) exposed through the AbstractPlot accessors. The navigation methods below are required by the Movable interface but are never invoked for scatter; they are inert stubs so that the previously duplicated (and already-diverged) plane navigation logic cannot be "fixed" here with no effect on runtime behavior.