DIAGNOSTIC: log ChartComponent.paint entry every frame

Native logs from 6ef4eb7 ruled out the leaked-mutable-target
hypothesis -- chart-line's drawTextureAlphaMaskImpl always reports
targetSet=0 (correctly routed to screen). Both chart-line (blank)
and chart-pie (working) emit ~70 bg fillRects between their last
chart paint and the screenshot, with no chart paints in between.
Yet pie shows pie content in the captured PNG and line shows pure
bg color.

Hypothesis: Form.paint is invoked at ~50fps (the bg fillRect
heartbeat) but ChartComponent.paint is being skipped on the chart-
line form for some reason -- maybe a dirty-region optimisation that
declares the chart "not invalidated", or an isVisible check, or
something specific to the chart.

Log every ChartComponent.paint call so we can see whether the
chart's paint method is being called every frame for chart-pie but
not for chart-line.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: shai-almog

CodenameOne/src/com/codename1/charts/ChartComponent.java

@@ -275,6 +275,7 @@ protected Dimension calcPreferredSize() {
     /// - `g`
     @Override
     public void paint(Graphics g) {
+        System.out.println("CN1SS:DBG:ChartComponent.paint chart=" + chart.getClass().getSimpleName());
         super.paint(g);
         boolean oldAntialias = g.isAntiAliased();
         g.setAntiAliased(true);