add documentation

Assets/Scripts/VoxelWorld/VoxelWorldSpawnAnchor.cs

@@ -3,10 +3,16 @@ using UnityEngine;
 namespace VoxelWorldScene
 {
     [DisallowMultipleComponent]
+    /// <summary>
+    /// Marks a scene transform that should contribute interest before players move so spawn areas can be prewarmed for nav coverage.
+    /// </summary>
     public sealed class VoxelWorldSpawnAnchor : MonoBehaviour
     {
         [SerializeField, Min(0.01f)] private float priority = 2f;
 
+        /// <summary>
+        /// Relative importance of this anchor when coverage planning competes between multiple spawn-related interests.
+        /// </summary>
         public float Priority => priority;
     }
 }