The Project panel's vertical scroll bar clamped its thumb between 16
points and the track's height. When the track was shorter than 16
points (an empty project in a 1280 x 800 browser window at device pixel
ratio 2, or any short panel), that clamp panicked on the first frame:
the browser canvas went blank and the app stopped responding. The
thumb is now at most the track's length, and both scroll bars share
the calculation.
Test: a_short_project_panel_draws (ui_project_rows).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
