feat(D.5.2): thread UiEffects through EntitySpawn + route 0x02CE PublicUpdatePropertyInt

- EntitySpawn record: add UiEffects = 0 field (after IconUnderlayId)
- EntitySpawn construction site: thread parsed.Value.UiEffects as the new tail arg
- WorldSession: declare ObjectIntPropertyUpdate payload record + ObjectIntPropertyUpdated event (after StateUpdated)
- Message loop: add else-if branch for PublicUpdatePropertyInt.Opcode (0x02CE), parses + fires ObjectIntPropertyUpdated

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/AcDream.Core.Net/WorldSession.cs

@@ -88,7 +88,10 @@ public sealed class WorldSession : IDisposable
         // (0x40000000) and WeenieHeaderFlag2.IconUnderlay (0x01) respectively.
         // Zero when the server did not send the field (common for most entities).
         uint IconOverlayId = 0,
-        uint IconUnderlayId = 0);
+        uint IconUnderlayId = 0,
+        // D.5.2 (2026-06-17): UiEffects bitfield (weenieFlags 0x80) — drives the icon's
+        // effect recolor. CreateObject-only; 0 = no effect.
+        uint UiEffects = 0);
 
     /// <summary>Fires when the session finishes parsing a CreateObject.</summary>
     public event Action<EntitySpawn>? EntitySpawned;
@@ -161,6 +164,20 @@ public sealed class WorldSession : IDisposable
     /// </summary>
     public event Action<SetState.Parsed>? StateUpdated;
 
+    /// <summary>
+    /// Payload for <see cref="ObjectIntPropertyUpdated"/>: a single PropertyInt change on
+    /// a visible object (from PublicUpdatePropertyInt 0x02CE). Subscribers map the
+    /// property to typed state (e.g. UiEffects → the item's icon effect).
+    /// </summary>
+    public readonly record struct ObjectIntPropertyUpdate(uint Guid, uint Property, int Value);
+
+    /// <summary>
+    /// Fires when the session parses a PublicUpdatePropertyInt (0x02CE) — one
+    /// PropertyInt updated on a visible object. D.5.2 routes UiEffects (18) to the
+    /// item repository so the icon re-composites live.
+    /// </summary>
+    public event Action<ObjectIntPropertyUpdate>? ObjectIntPropertyUpdated;
+
     /// <summary>
     /// Fires when the server sends a PlayerTeleport (0xF751) game message,
     /// signalling that the player is entering portal space. The uint payload
@@ -727,7 +744,8 @@ public sealed class WorldSession : IDisposable
                         parsed.Value.UseRadius,
                         parsed.Value.IconId,
                         parsed.Value.IconOverlayId,
-                        parsed.Value.IconUnderlayId));
+                        parsed.Value.IconUnderlayId,
+                        parsed.Value.UiEffects));
                 }
             }
             else if (op == DeleteObject.Opcode)
@@ -901,6 +919,13 @@ public sealed class WorldSession : IDisposable
                 if (parsed is not null)
                     VitalCurrentUpdated?.Invoke(parsed.Value);
             }
+            else if (op == PublicUpdatePropertyInt.Opcode)
+            {
+                var p = PublicUpdatePropertyInt.TryParse(body);
+                if (p is not null)
+                    ObjectIntPropertyUpdated?.Invoke(
+                        new ObjectIntPropertyUpdate(p.Value.Guid, p.Value.Property, p.Value.Value));
+            }
             else if (op == GameEventEnvelope.Opcode)
             {
                 // Phase F.1: 0xF7B0 is the GameEvent envelope. Parse the