Use typed stat modifier behavior kind

Assets/Scripts/UI/Properties Panel/PropertiesPanel.cs

@@ -439,7 +439,7 @@ public class PropertiesPanel : MonoBehaviour
 		var sheet = AddStatSheet();
 		foreach (var behavior in typedItem?.BehaviorPayloads ?? Array.Empty<AetheriaRuntimeBehaviorPayload>())
 		{
-			if (string.Equals(behavior.Kind, nameof(StatModifierData), StringComparison.Ordinal))
+			if (string.Equals(behavior.Kind, AetheriaRuntimeBehaviorKinds.StatModifier, StringComparison.Ordinal))
 			{
 				var statReference = ReadTypedStatReference(FindTypedBehaviorField(behavior, 1)?.Value);
 				var modifier = ReadTypedPerformanceStat(FindTypedBehaviorField(behavior, 2)?.Value);

Packages/org.gamecult.aetheria.state/Runtime/AetheriaRuntimeBehaviorKinds.cs

@@ -5,6 +5,7 @@ namespace GameCult.Aetheria.State.Unity
 {
     public static class AetheriaRuntimeBehaviorKinds
     {
+        public const string StatModifier = "StatModifier";
         public const string GuidedWeapon = "GuidedWeapon";
         public const string Launcher = "Launcher";
         public const string InstantWeapon = "InstantWeapon";

docs/aetheria-perfect-machine-map.md

@@ -225,10 +225,11 @@ legacy catalog cache, and legacy UI paths should be migration-only or deleted.
   manufacturer, base mass, max durability, thermal bounds, and thermal
   performance curve keys for basic item presentation without hydrating legacy
   DTOs. Runtime behavior stat display and damage-range curves read typed
-  behavior payload fields by legacy payload key. Damage-range payload selection
-  is keyed by package-owned typed weapon behavior metadata; legacy
-  `BehaviorData` ancestry is no longer a fallback for weapon payload selection.
-  The old explicit
+  behavior payload fields by legacy payload key; stat modifier presentation
+  checks the package-owned typed `StatModifier` kind instead of a legacy data
+  class name. Damage-range payload selection is keyed by package-owned typed
+  weapon behavior metadata; legacy `BehaviorData` ancestry is no longer a
+  fallback for weapon payload selection. The old explicit
   `Inspect(ItemData)` DTO inspection overload is deleted; trade row clicks now
   inspect the typed runtime catalog row directly. Incomplete typed thermal
   curve rows render a neutral fallback curve instead of hydrating legacy
@@ -761,6 +762,8 @@ First Aetheria surfaces to publish:
      curves onto typed behavior payload fields, and delete the explicit
      `Inspect(ItemData)` projection inspector after moving trade row inspection
      onto typed runtime catalog rows.
+   - Done: replace the PropertiesPanel stat modifier class-name check with the
+     package-owned typed `StatModifier` behavior kind.
    - Done: demote PropertiesPanel weapon damage-range payload matching from
      `BehaviorData` `Type` authority to package-owned typed weapon behavior
      metadata; `BehaviorData` reflection remains display/filter metadata-only