Every node stops at the width it was built for when it is dragged narrower:
the growing panels and the fixed cards. Load Video's IN and OUT boxes stay
whole in a narrow node.
The frontend adds 104 pixels to a growing panel's minimum width and leaves a
fixed-height card's minimum out of its width sum, so a card fell to a 210
pixel default. Panels pass exactMinWidth to fillNodeHeight or call
holdNodeMinWidth, and tests/panel_guards.test.mjs fails a new panel that does
neither.
ausboss
5a4674f5f6