Subgraph Box Geo Transform

After graph.CreateGeometryGraph(), each Node has populated geometry. When we write to SVG we use a transpose to flip y-coordinate (TransformGraphByFlippingY). This does not touch the geometry on the subgraph, making the node and edge geo not intersect with the subgraph box, this only becomes an issue when wanting to draw the subgraph (for example, as a box).
There are two ways around this:

1. Manually transpose the GeometryNode on the subgraph before using the subgraph geo:

graph.RootSubgraph.AllSubgraphsDepthFirstExcludingSelf()
|> Seq.iter (fun e -> e.GeometryNode.Transform(PlaneTransformation(1., 0., 0., 0., -1., 0.)))

2. Add the actual subgraph to the geometry, after CreateGeometryGraph, before using the subgraph geometry (e.g. SvgWriter)

graph.GeometryGraph.Nodes.Add(actualSubgraph.GeometryNode)

I am not sure which is the correct way of doing it, but provided they both occur post-layout, it shouldn't affect things dramatically

I don't think this is a bug, but it took me a good couple hours so solve, so I wanted to document somewhere others could find it.

Start with the CreateGeometryGraph, TransformGraphByFlippingY, and SvgWriter entry points mentioned in the report, then compare the two post-layout workarounds for subgraph geometry. Document the confirmed approach and the conditions under which subgraph boxes align with their nodes and edges.