A screen that draws its card once and holds it no longer leaves the web preview black: DisplayManager remembers a changed frame the snapshot throttle skipped, and the render loop writes it (write_owed_snapshot(), called from _display_once) once the interval has passed. A failed owed write stays owed and is retried.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
