feat(rflows): Sankey-consistent edge widths, split controls, vessel path fixes
- Add computeFlowWidths() pre-pass for per-node proportional edge widths
(outgoing edges sum to node pipe width, 8-80px range)
- Replace +/- buttons on edges with draggable split controls on nodes
(source, funnel spending, funnel overflow — min 5% clamp, 60fps updates)
- Fix vessel wall path discontinuities by interpolating at pipe boundaries
- Stabilize overflow pipe sizing (fixed height, CSS opacity transitions)
- Tighten funnel foreignObject bounds to eliminate pointer-events overlap
- Replace foreignObject zone/overflow labels with SVG <text> elements
- Add inflow pipe indicator bars on funnels showing flow fill ratio
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
e6f78a67e8