A highlight that travels through the glyphs

TextStyle takes a Brush. Animate the gradient's startX/endX and the text shimmers — not a rectangle over it, not a masked copy of it. Nothing has to measure the label, so it keeps working at any width, in any language, wrapped or not.

// adapted — the transition is declared OUTSIDE the gate that shows the label
val sweep = rememberInfiniteTransition(label = "sweep")
val head by sweep.animateFloat(
    initialValue = 0f, targetValue = 1f,
    animationSpec = infiniteRepeatable(tween(3200, easing = LinearEasing), RepeatMode.Restart),
    label = "sweepHead",
)