added inventory and stamina system

Assets/Scripts/ItemDefinition.cs

@@ -0,0 +1,28 @@
+using UnityEngine;
+
+/// <summary>
+/// Create via right-click → Create → OGG → Item Definition
+/// Drag onto PickupItem components in the scene.
+/// </summary>
+[CreateAssetMenu(fileName = "New Item", menuName = "OGG/Item Definition")]
+public class ItemDefinition : ScriptableObject
+{
+    public enum ItemType { Misc, Consumable, Weapon }
+
+    [Header("Identity")]
+    public string   itemName    = "Unnamed Item";
+    public Sprite   icon;
+    public ItemType type        = ItemType.Misc;
+
+    [Header("Weapon (only if type == Weapon)")]
+    [Tooltip("The prefab that gets spawned in the weapon holder when this is equipped.")]
+    public GameObject weaponPrefab;
+
+    [Header("Equipment")]
+    [Tooltip("If true, this item can be equipped/unequipped from the inventory even if it isn't a weapon.")]
+    public bool isEquippable = false;
+
+    [Header("Flavour")]
+    [TextArea(2, 4)]
+    public string description = "";
+}