Update scene document validation for NPC entities

src/document/scene-document-validation.ts

@@ -3348,13 +3348,14 @@ function validateInteractionLink(
 
   if (
     sourceEntity.kind !== "triggerVolume" &&
-    sourceEntity.kind !== "interactable"
+    sourceEntity.kind !== "interactable" &&
+    sourceEntity.kind !== "npc"
   ) {
     diagnostics.push(
       createDiagnostic(
         "error",
         "invalid-interaction-source-kind",
-        "Interaction links may only source from Trigger Volume or Interactable entities in the current slice.",
+        "Interaction links may only source from Trigger Volume, Interactable, or NPC entities in the current slice.",
         `${path}.sourceEntityId`
       )
     );
@@ -3382,6 +3383,17 @@ function validateInteractionLink(
         )
       );
     }
+  } else if (sourceEntity.kind === "npc") {
+    if (link.trigger !== "click") {
+      diagnostics.push(
+        createDiagnostic(
+          "error",
+          "unsupported-interaction-trigger",
+          "NPC links may only use the click trigger.",
+          `${path}.trigger`
+        )
+      );
+    }
   }
 
   switch (link.action.type) {