Invalid node or viewport

A node handle does not exist in the retained tree, or the viewport size is not finite and positive.

#Common causes

• A handle from a previous mount was reused after a rebuild.
• A window reported a zero or NaN size.

#Fixes

• Look nodes up again by ID after each mount; skip frames while minimized.

• Code: ARA4040

• Constant: ui::NODE

• Reported by: ara-ui