adapted wire stubs with auto side detection

src/util.typ

@@ -73,4 +73,15 @@
 #let valid-anchors = (
   "center", "north", "east", "west", "south",
   "north-east", "north-west", "south-east", "south-west"
-)
+)
+
+#let get-port-side(element, port) = {
+  for (side, ports) in element.ports {
+    for p in ports {
+      if p.id == port {
+        return side
+      }
+    }
+  }
+  panic("Unknown port " + port + " on element " + element.id)
+}