LANTERN purge B7: rename CharacterId -> FrameKind (frame terminology)

Enum renamed in StatIds.cs (byte values unchanged - serialized definitions/saves
never re-mean); all call sites + doc mentions swept (ClassTraits, PlayerAuthoring,
CharacterStatsDefinition field type, menu/UI, tests). CharacterStatsDefinition SO
CLASS name kept (asset-binding risk; deferred per plan). 390 green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Assets/_Project/Scripts/Authoring/Combat/AbilityDatabaseAuthoring.cs

@@ -19,7 +19,7 @@ namespace ProjectM.Authoring
         [Tooltip("All ability definitions available in the game. Indexed at runtime by AbilityId.")]
         public List<AbilityDefinition> Abilities = new List<AbilityDefinition>();
 
-        [Tooltip("All character-stats definitions. Indexed at runtime by CharacterId.")]
+        [Tooltip("All character-stats definitions. Indexed at runtime by FrameKind.")]
         public List<CharacterStatsDefinition> Characters = new List<CharacterStatsDefinition>();
 
         private class DatabaseBaker : Baker<AbilityDatabaseAuthoring>

Assets/_Project/Scripts/Authoring/Combat/CharacterStatsDefinition.cs

@@ -11,7 +11,7 @@ namespace ProjectM.Authoring
     [CreateAssetMenu(menuName = "Project M/Character Stats Definition", fileName = "Character_")]
     public class CharacterStatsDefinition : ScriptableObject
     {
-        public CharacterId Id = CharacterId.Default;
+        public FrameKind Id = FrameKind.Default;
         public string DisplayName = "Character";
 
         [Min(0f)] public float MoveSpeed = 6f;

Assets/_Project/Scripts/Authoring/Player/PlayerAuthoring.cs

@@ -43,7 +43,7 @@ namespace ProjectM.Authoring
                 if (authoring.Character != null) DependsOn(authoring.Character);
 
                 byte characterId = authoring.Character != null
-                    ? (byte)authoring.Character.Id : (byte)CharacterId.Default;
+                    ? (byte)authoring.Character.Id : (byte)FrameKind.Default;
                 float maxHealth = authoring.Character != null
                     ? authoring.Character.MaxHealth : authoring.FallbackMaxHealth;