@mytec: iter3.5.1 ready for testing

frontend/src/components/map/CoverageBoundary.tsx

@@ -107,7 +107,10 @@ export default function CoverageBoundary({
 /**
  * Compute concave hull boundary path(s) for a set of coverage points.
  *
- * maxEdge = resolution * 3 (in km) gives good detail without over-fitting.
+ * Uses adaptive maxEdge based on point count and resolution:
+ * - More points → smaller maxEdge for finer detail
+ * - Larger resolution → larger maxEdge to avoid over-fitting
+ *
  * Returns multiple paths if hull is a MultiPolygon (disjoint coverage areas).
  * Falls back to empty if hull computation fails (e.g., collinear points).
  */
@@ -121,8 +124,17 @@ function computeConcaveHulls(
   const features = pts.map((p) => point([p.lon, p.lat]));
   const fc = featureCollection(features);
 
-  // maxEdge in km — resolution * 3 balances detail vs smoothness
-  const maxEdge = (resolutionM * 3) / 1000;
+  // Adaptive maxEdge based on point density:
+  // - Base: resolution * 2 (tighter fit)
+  // - For sparse grids (<100 pts): use larger edge to avoid holes
+  // - For dense grids (>1000 pts): use smaller edge for detail
+  let multiplier = 2.0;
+  if (pts.length < 100) {
+    multiplier = 4.0; // Sparse: wider tolerance
+  } else if (pts.length > 1000) {
+    multiplier = 1.5; // Dense: finer detail
+  }
+  const maxEdge = (resolutionM * multiplier) / 1000;
 
   try {
     const hull = concave(fc, { maxEdge, units: 'kilometers' });