feat(ui): port retail selected-item mana

Parse and route the complete 0x0264 guid/fraction/valid response, send exact 0x0263 item-mana queries, and reproduce retail meter visibility plus guid-zero cancellation for mana and health selection changes. Keep the behavior in Core state and the retained selected-object controller with wire/state/UI conformance coverage.

Co-Authored-By: Codex <codex@openai.com>

src/AcDream.App/Rendering/GameWindow.cs

@@ -728,6 +728,7 @@ public sealed class GameWindow : IDisposable
     // SetTurbineChatChannels (0x0295) shortly after EnterWorld.
     public readonly AcDream.Core.Chat.TurbineChatState TurbineChat = new();
     public readonly AcDream.Core.Combat.CombatState Combat = new();
+    public readonly AcDream.Core.Items.ItemManaState ItemMana = new();
     // Issue #11 — load static spell metadata from data/spells.csv at startup.
     // Provides Family for buff stacking (issue #6) + names + icons + tooltips
     // for the future Spellbook panel. The CSV is copied to bin/<config>/net10.0/data/
@@ -2117,6 +2118,7 @@ public sealed class GameWindow : IDisposable
                         (type, icon, under, over, effects) => iconComposer.GetIcon(type, icon, under, over, effects),
                         UseItemByGuid,
                         Combat,
+                        ItemMana,
                         ToggleLiveCombatMode,
                         _itemInteractionController,
                         entry => _liveSession?.SendAddShortcut(entry),
@@ -2130,6 +2132,7 @@ public sealed class GameWindow : IDisposable
                         Combat.HasHealth,
                         guid => (uint)(Objects.Get(guid)?.StackSize ?? 0),
                         guid => _liveSession?.SendQueryHealth(guid),
+                        guid => _liveSession?.SendQueryItemMana(guid),
                         () => _playerServerGuid,
                         (item, container, placement) =>
                             _liveSession?.SendPutItemInContainer(item, container, placement)),
@@ -2590,7 +2593,8 @@ public sealed class GameWindow : IDisposable
                 },
                 onShortcuts: list => Shortcuts = list,
                 playerGuid: () => _playerServerGuid,
-                onUseDone: error => _itemInteractionController?.CompleteUse(error));
+                onUseDone: error => _itemInteractionController?.CompleteUse(error),
+                itemMana: ItemMana);
 
             // Phase I.7: subscribe to CombatState events and emit
             // retail-faithful "You hit X for Y damage" chat lines into