requestRepaint method
void
requestRepaint()
Notifies repaint listeners at most once per vsync.
Why: interactive TUI drains can apply many MirrorGrid updates per frame; notifying on each apply schedules redundant CustomPaint work and floods Frame Request Pending. Dirty rows accumulate until the coalesced paint. Deferred to post-frame when called from layout so dependents do not setState during build.
Also used after a deferred glyph-atlas rebuild so CustomPaint(repaint: grid) actually paints the newly atlased glyphs (scheduleFrame alone
does not mark the render object dirty).
Implementation
void requestRepaint() => _notifyRepaint();