feat: Adds Mobile.Murderer virtual property, consolidates kill-threshold checks (#2355)

## Summary

- Adds `public virtual bool Murderer => Kills >= 5` property to `Mobile`, replacing ~30 scattered `Kills >= 5` / `Kills < 5` magic-number checks across the codebase
- `BaseCreature` overrides `Murderer` to also return `true` when `AlwaysMurderer` is set
- Updates `Corpse` serialization to v15, storing `_murderer` as a `bool` field (migrated from `int Kills >= 5` in earlier versions)

Projects/UOContent/Mobiles/BaseCreature.cs

@@ -557,6 +557,8 @@ namespace Server.Mobiles
 
         public virtual bool AlwaysMurderer => false;
 
+        public override bool Murderer => AlwaysMurderer || base.Murderer;
+
         public virtual bool AlwaysAttackable => false;
 
         [CommandProperty(AccessLevel.GameMaster)]
@@ -2806,7 +2808,7 @@ namespace Server.Mobiles
                 return;
             }
 
-            if (!Body.IsHuman || Kills >= 5 || AlwaysMurderer || AlwaysAttackable || m.Kills < 5 ||
+            if (!Body.IsHuman || Murderer || AlwaysAttackable || !m.Murderer ||
                 !m.InRange(Location, 12) || !m.Alive)
             {
                 return;

Projects/UOContent/Mobiles/Healers/Healer.cs

@@ -48,7 +48,7 @@ public partial class Healer : BaseHealer
             return false;
         }
 
-        if (m.Kills >= 5)
+        if (m.Murderer)
         {
             Say(501223); // Thou'rt not a decent and good person. I shall not resurrect thee.
             return false;

Projects/UOContent/Mobiles/Healers/WanderingHealer.cs

@@ -40,7 +40,7 @@ public partial class WanderingHealer : BaseHealer
             return false;
         }
 
-        if (m.Kills >= 5)
+        if (m.Murderer)
         {
             Say(501223); // Thou'rt not a decent and good person. I shall not resurrect thee.
             return false;

Projects/UOContent/Mobiles/Monsters/Misc/Magic/EtherealWarrior.cs

@@ -70,7 +70,7 @@ namespace Server.Mobiles
                     InLOS(from))
                 {
                     m_NextResurrect = Core.Now + ResurrectDelay;
-                    if (!from.Criminal && from.Kills < 5 && from.Karma > 0)
+                    if (!from.Criminal && !from.Murderer && from.Karma > 0)
                     {
                         if (from.Map?.CanFit(from.Location, 16, false, false) == true)
                         {

Projects/UOContent/Mobiles/PlayerMobile.cs

@@ -2595,7 +2595,7 @@ namespace Server.Mobiles
                 }
             }
 
-            if (Kills >= 5 && Core.Now >= m_NextJustAward)
+            if (Murderer && Core.Now >= m_NextJustAward)
             {
                 var m = FindMostRecentDamager(false);
 

Projects/UOContent/Mobiles/Special/BaseChampion.cs

@@ -165,7 +165,7 @@ public abstract partial class BaseChampion : BaseCreature
 
         var prot = JusticeVirtue.GetProtector(pm);
 
-        if (prot == null || prot.Map != pm.Map || prot.Kills >= 5 || prot.Criminal ||
+        if (prot == null || prot.Map != pm.Map || prot.Murderer || prot.Criminal ||
             !JusticeVirtue.CheckMapRegion(pm, prot))
         {
             return;

Projects/UOContent/Mobiles/Special/Harrower.cs

@@ -279,7 +279,7 @@ public partial class Harrower : BaseCreature
 
             var prot = JusticeVirtue.GetProtector(pm);
 
-            if (prot == null || prot.Map != pm.Map || prot.Kills >= 5 || prot.Criminal ||
+            if (prot == null || prot.Map != pm.Map || prot.Murderer || prot.Criminal ||
                 !JusticeVirtue.CheckMapRegion(pm, prot))
             {
                 continue;