Update Healer Man server

scripts/runewaker-pipeline/lib/environment-assembly.mjs

@@ -81,6 +81,31 @@ export function transformSourcePointToPrimaryThree(
   return [point.x * meters, point.y * meters, -point.z * meters];
 }
 
+export function transformSourceHeadingToPrimaryThree(sourceYawRadians, primary) {
+  const yaw = Number(sourceYawRadians);
+  if (!Number.isFinite(yaw)) throw new Error("sourceYawRadians must be finite.");
+  const rotation = new Quaternion(...finiteTuple(primary?.rotation, 4, "primary.rotation"));
+  if (rotation.lengthSq() < 1e-12) throw new Error("primary.rotation cannot be zero.");
+  rotation.normalize().invert();
+  const scale = finiteTuple(primary?.scale, 3, "primary.scale");
+  if (scale.some((value) => Math.abs(value) < 1e-12)) {
+    throw new Error("primary.scale cannot contain zero.");
+  }
+
+  // RuneWaker's left-handed forward is -Z at yaw zero. Rotate in the source
+  // basis first, apply inverse primary scale, then reflect Z into Three.js and
+  // normalize the planar vector.
+  const forward = new Vector3(Math.sin(yaw), 0, -Math.cos(yaw)).applyQuaternion(rotation);
+  forward.set(forward.x / scale[0], forward.y / scale[1], forward.z / scale[2]);
+  forward.y = 0;
+  forward.z *= -1;
+  const length = Math.hypot(forward.x, forward.z);
+  if (!Number.isFinite(length) || length < 1e-8) {
+    throw new Error("Source heading collapsed when transformed into the primary frame.");
+  }
+  return [forward.x / length, 0, forward.z / length];
+}
+
 function cloneNodeTree(document, node) {
   const clone = document.createNode(node.getName())
     .setMatrix(node.getMatrix())