Root cause of the popup's fit/center failure: PlanDiagram rendered
w-full inside the popup's shrink-to-fit absolute wrapper — the svg
resolved to the popup's width regardless of its viewBox extent, so the
transform math (1 svg unit = 1 px at zoom 1) was off and the 'fit floor'
neither fitted nor centered.
- naturalSize: the popup's diagram renders at the viewBox width in px,
so fit/pan/zoom math holds.
- The popup's fit box is now the PADDED ink box (GRAPH_PAD all around):
centered strokes and the glow halo never clip at the frame edge.
- fitZoomFor lost its 0.15 artificial floor — for wide graphs it sat
ABOVE the true fit and broke 'fully zoomed out = the whole graph
visible, whichever axis binds' (owner's rule). The fit itself is the
floor; a 0.02 epsilon only guards degenerate viewports.
amosblomqvist
6464b34a79