Consolidate third-party plugins into Assets/Plugins

Move and consolidate many third-party plugin files and metadata from various locations (notably Assets/Third Parties/Plugins 1 and scattered Opsive/Photon folders) into a unified Assets/Plugins directory. Includes DOTween, PrimeTween, Native/BackroomsNoise, Sirenix/Odin Inspector, and Opsive UltimateCharacterController/shared libs, plus updates to several .meta files and removal of obsolete installer/legacy files. This standardizes plugin layout and cleans up duplicate/obsolete assets.

Assets/Third Parties/Opsive/UltimateCharacterController/Scripts/VR/IVRHandHandler.cs

@@ -0,0 +1,36 @@
+/// ---------------------------------------------
+/// Ultimate Character Controller
+/// Copyright (c) Opsive. All Rights Reserved.
+/// https://www.opsive.com
+/// ---------------------------------------------
+
+namespace Opsive.UltimateCharacterController.VR
+{
+    using UnityEngine;
+
+    /// <summary>
+    /// The handler for the VR hands.
+    /// </summary>
+    public interface IVRHandHandler
+    {
+        /// <summary>
+        /// Returns the number of slots that the hands can occupy.
+        /// </summary>
+        /// <returns>The number of slots that the hands can occupy.</returns>
+        int GetSlotCount();
+
+        /// <summary>
+        /// Returns the hand GameObject at the specified slot ID.
+        /// </summary>
+        /// <param name="slotID">The ID to retrieve the hand of.</param>
+        /// <returns>The hand GameObject at the specified slot ID.</returns>
+        GameObject GetHand(int slotID);
+
+        /// <summary>
+        /// Returns the velocity of the hand at the specified slot.
+        /// </summary>
+        /// <param name="slotID">The slot to get the velocity of.</param>
+        /// <returns>The velocity of the hand at the specifeid slot.</returns>
+        Vector3 GetVelocity(int slotID);
+    }
+}