Feature: Animating the touch cursor

Currently the touch cursor appears and moves side to side without an animation. How difficult would it be to animate it so the movement is more natural and smooth looking?

No file, test, or entry point is named. Start by locating the touch cursor implementation in the fl_chart repository and review how its current side-to-side movement is handled; clarify the intended animation and verify that the cursor movement looks smooth without breaking existing touch interaction behavior.

Written by the indexing model from the issue text.