feat(runtime): own character selection flow

src/AcDream.Runtime/GameRuntimeViews.cs

@@ -1,5 +1,6 @@
 using AcDream.Core.Physics;
 using AcDream.Runtime.World;
+using AcDream.Runtime.Session;
 
 namespace AcDream.Runtime;
 
@@ -275,6 +276,10 @@ public interface IGameRuntimeView
 
     IRuntimeChatView Chat { get; }
 
+    IRuntimeCharacterSelectionView CharacterSelection =>
+        throw new NotSupportedException(
+            "This runtime view does not project character selection.");
+
     IRuntimeFellowshipView Fellowship { get; }
 
     IRuntimeAllegianceView Allegiance { get; }