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/Simulation/Meta/MetaCatalog.cs

@@ -7,7 +7,7 @@ namespace ProjectM.Simulation
     /// One authored PERMANENT meta upgrade: tiered (buy tier owned+1 up to <see cref="MaxTier"/>), priced in Aether
     /// with a linear ramp (<c>cost(owned) = BaseCost + owned*CostGrowth</c>), class-gated by <see cref="ClassMask"/>
     /// (bit0 = Warrior, bit1 = Ranger — resolve via <see cref="BoonMath.MaskFor"/>, NEVER a raw <c>1&lt;&lt;ClassId</c>:
-    /// the stored ClassId is the normalized CharacterId 2/3). <see cref="Id"/> is the stable APPEND-ONLY key
+    /// the stored ClassId is the normalized FrameKind 2/3). <see cref="Id"/> is the stable APPEND-ONLY key
     /// persisted in SaveData v6 and keyed into the live StatModifier as <c>Tuning.MetaSourceIdBase + Id</c>.
     /// DISTINCT from <see cref="BoonDefBlob"/> — boons are run-scoped single-shots; overloading one catalog would
     /// blur the two channels (DR-037). <see cref="PrereqId"/> = 0xFF means no prerequisite (v1 ships a FLAT catalog