The composer (and any bottom-most pane content) ran flush into the
window's bottom resize-drag strip when the status bar was hidden, since
the bar normally covers that edge. Reserve ClideResizeBorder.edgeThickness
as a bottom inset in RootLayout whenever the status bar is not visible, so
the interaction zone bottom-anchors consistently either way.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>