feat: add channel enable/disable, prefab docs, and UI updates

Add per-channel enable/disable toggle to the in-game logging system
with Enable()/Disable() on InGameLogger and EnableChannel/DisableChannel
on IGameLogStore. Update README with prefab setup guide and enable/disable
documentation. Update character creation and log container prefabs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Assets/Code/GameState/UI/CharacterCreationReference.cs

@@ -1,3 +1,4 @@
+using Jovian.InGameLogging.UI;
 using TMPro;
 using UnityEngine;
 using UnityEngine.UI;
@@ -20,6 +21,7 @@ namespace Nox.UI {
         //center
         public Button backButtonCenter;
         public Button acceptButton;
+        public GameLogView gameLogView;
 
         //right
         public Image portraitImage;