035c86ced9
Adds a --use-cords switch to tro_flow.py (--use-coords accepted too). With it, every TRO node carries its plant coordinate as a pos attribute and the SVG is produced by "neato -n" instead of dot, so the diagram looks like the plant layout rather than a computed left-to-right flow. Scale is 0.25 pt/mm (COORD_SCALE), which turns the ~11 x 20 m plant into roughly 2800 x 5000 pt - large enough that the TRO boxes do not overlap. Without the switch the pos attributes stay in the DOT as information only, at 1:100, and dot ignores them; the default layout is unchanged. Two details neato -n needs: the legend gets a position of its own, placed below left of the plant bounding box, because with -n a node without pos would land at 0,0 in the middle of the drawing. And the switch is refused with a clear message if any TRO has no coordinate, since -n cannot lay out a graph with missing positions. Verified that neato -n reproduces the given coordinates: the positions it reports back differ from the input by a constant offset only (spread 0.08 pt, from Graphviz moving the drawing into the positive quadrant), and no node distance changes by more than 0.08 pt over spans of up to 3600 pt. graph_to_svg() in material_flow.py replaces dot_to_svg() to take an engine and the no-op flag; dot_to_svg() stays as a thin wrapper. It now also treats output on stderr as an error, so neato's "node has no position" warnings do not pass silently. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>