Add tracking pins for offscreen targets

Assets/Scripts/UI/Tracking/TrackingDistanceSource.cs

@@ -0,0 +1,43 @@
+using UnityEngine;
+
+namespace UI.Tracking
+{
+    /// <summary>
+    /// Marks a GameObject as the source point for distance calculations in the tracking system.
+    /// Typically attached to the player or camera. Only one should be active at a time.
+    /// </summary>
+    public class TrackingDistanceSource : MonoBehaviour
+    {
+        private static TrackingDistanceSource _instance;
+
+        /// <summary>
+        /// The currently active distance source (typically the player)
+        /// </summary>
+        public static TrackingDistanceSource Instance => _instance;
+
+        /// <summary>
+        /// The world position of this distance source
+        /// </summary>
+        public Vector3 WorldPosition => transform.position;
+
+        private void OnEnable()
+        {
+            // Set as the active instance
+            if (_instance != null && _instance != this)
+            {
+                Debug.LogWarning($"[TrackingDistanceSource] Multiple distance sources detected. Overwriting previous instance ({_instance.name}) with {name}");
+            }
+            _instance = this;
+        }
+
+        private void OnDisable()
+        {
+            // Clear instance if this was the active one
+            if (_instance == this)
+            {
+                _instance = null;
+            }
+        }
+    }
+}
+