Enhance ability validation: add method to check if an ability can be resolved without deep copy and prune invalid unlocked abilities during load

src/main/java/kamkeel/npcs/controllers/data/ability/AbilityController.java

@@ -340,6 +340,37 @@ public class AbilityController implements IAbilityHandler {
         return builtAbilities.containsKey(key) || customAbilities.containsKey(key);
     }
 
+    /**
+     * Check if a key can be resolved to a valid ability without creating a deep copy.
+     * Uses the same lookup chain as {@link #resolveAbility(String)}.
+     */
+    public boolean canResolveAbility(String key) {
+        if (key == null || key.isEmpty()) return false;
+
+        // Built-in: exact name
+        if (builtAbilities.containsKey(key)) return true;
+
+        // Built-in: case-insensitive name
+        for (String name : builtAbilities.keySet()) {
+            if (name.equalsIgnoreCase(key)) return true;
+        }
+
+        // Built-in: registry key / ID
+        for (Ability ability : builtAbilities.values()) {
+            if (ability.getId() != null && ability.getId().equalsIgnoreCase(key)) return true;
+        }
+
+        // Custom: exact UUID
+        if (customAbilities.containsKey(key)) return true;
+
+        // Custom: case-insensitive name
+        for (Ability ability : customAbilities.values()) {
+            if (ability.getName() != null && ability.getName().equalsIgnoreCase(key)) return true;
+        }
+
+        return false;
+    }
+
     // ═══════════════════════════════════════════════════════════════════════════
     // EXTENSION POINTS
     // ═══════════════════════════════════════════════════════════════════════════

src/main/java/noppes/npcs/controllers/data/PlayerAbilityData.java

@@ -15,6 +15,7 @@ import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.nbt.NBTTagList;
 import net.minecraft.nbt.NBTTagString;
 import net.minecraft.util.DamageSource;
+import noppes.npcs.LogWriter;
 import noppes.npcs.api.ability.IPlayerAbilityData;
 import noppes.npcs.controllers.AnimationController;
 import noppes.npcs.controllers.data.Animation;
@@ -23,6 +24,7 @@ import kamkeel.npcs.network.packets.data.ability.PlayerAbilityStatePacket;
 import kamkeel.npcs.network.packets.data.ability.PlayerAbilitySyncPacket;
 
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 
 /**
@@ -860,9 +862,30 @@ public class PlayerAbilityData implements IPlayerAbilityData {
             }
         }
         selectedIndex = compound.getInteger("PlayerAbilitySelected");
+
+        // Prune abilities that no longer exist (deleted custom abilities or removed built-ins)
+        validateUnlockedAbilities();
+
         if (selectedIndex >= unlockedAbilities.size()) {
             selectedIndex = Math.max(0, unlockedAbilities.size() - 1);
         }
         playingAbilityAnimation = compound.getBoolean("AbilityAnimating");
     }
+
+    /**
+     * Remove any unlocked ability keys that can no longer be resolved.
+     * Called during load to clean up references to deleted abilities.
+     */
+    private void validateUnlockedAbilities() {
+        if (AbilityController.Instance == null) return;
+
+        Iterator<String> it = unlockedAbilities.iterator();
+        while (it.hasNext()) {
+            String key = it.next();
+            if (!AbilityController.Instance.canResolveAbility(key)) {
+                it.remove();
+                LogWriter.info("Removed invalid ability reference from player data: " + key);
+            }
+        }
+    }
 }