Sharp corners for tight doglegs (both segments < 30px)

When both segments at a bend point are under 30px, the curved corner
radius creates a visible S-curve artifact. Using r=0 (sharp 90-degree
corner) eliminates the kink. Smooth curves reserved for longer segments.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Workflow/__Libraries/StellaOps.Workflow.Renderer.Svg/WorkflowRenderSvgRenderer.cs

@@ -2089,6 +2089,13 @@ public sealed class WorkflowRenderSvgRenderer
             var lenOut = Math.Sqrt((dxOut * dxOut) + (dyOut * dyOut));
 
             var r = Math.Min(radius, Math.Min(lenIn / 3d, lenOut / 3d));
+            // Sharp corner for tight doglegs: when both segments are short,
+            // a curved corner creates a visible S-curve. Sharp is cleaner.
+            if (lenIn < 30d && lenOut < 30d)
+            {
+                r = 0d;
+            }
+
             if (r < 0.5d || lenIn < 1d || lenOut < 1d)
             {
                 builder.Append($" L {Format(curr.X + offsetX)},{Format(curr.Y + offsetY)}");