Fix dangling topology edge by routing wide ETL paths below intermediate nodes

ui/src/components/features/PlatformTopology.tsx

@@ -168,12 +168,26 @@ function nodeCoords(col: number, row: number, rows: number) {
   }
 }
 
-/** Curved path — arcs upward for backward (orchestration) flows */
-function flowPath(x1: number, y1: number, x2: number, y2: number, backward = false) {
+/** Curved path — route edges to avoid dangling stubs over intermediate nodes */
+function flowPath(
+  x1: number, y1: number, x2: number, y2: number,
+  opts: { backward?: boolean; sameCol?: boolean } = {},
+) {
+  const { backward = false, sameCol = false } = opts
   if (backward || x2 < x1 - 2) {
     const arcY = Math.min(y1, y2) - 14
     return `M ${x1} ${y1} C ${x1} ${arcY}, ${x2} ${arcY}, ${x2} ${y2}`
   }
+  if (sameCol) {
+    const cx = (x1 + x2) / 2
+    return `M ${x1} ${y1} C ${cx} ${y1}, ${cx} ${y2}, ${x2} ${y2}`
+  }
+  const span = x2 - x1
+  const dy = Math.abs(y2 - y1)
+  if (span > 16 && dy > 4) {
+    const dipY = Math.max(y1, y2) + Math.min(12, 6 + span * 0.08)
+    return `M ${x1} ${y1} C ${x1 + span * 0.2} ${dipY}, ${x2 - span * 0.2} ${dipY}, ${x2} ${y2}`
+  }
   const mx = (x1 + x2) / 2
   return `M ${x1} ${y1} C ${mx} ${y1}, ${mx} ${y2}, ${x2} ${y2}`
 }
@@ -339,7 +353,7 @@ export function PlatformTopology({ workload, animations, selectedNodeId, onNodeC
             const backward = edge.kind === 'orchestration' && pb.col < pa.col
             const fromX = backward ? a.inX + (a.outX - a.inX) * 0.15 : a.outX
             const toX = backward ? b.outX - (b.outX - b.inX) * 0.15 : b.inX
-            const d = flowPath(fromX, a.y, toX, b.y, backward)
+            const d = flowPath(fromX, a.y, toX, b.y, { backward, sameCol: pa.col === pb.col })
             const live = edgesLive
             const dur = 1.8 + (i % 5) * 0.35
             return (