Fix MaleExplorer setup with shadow material and editor diagnostics.

Improve FBX/prefab import setup, CharacterSpawner, and add M3 inspect/rebuild helpers.

Co-authored-by: Cursor <cursoragent@cursor.com>

AIClient/Assets/Bundles/Characters/MaleExplorer/MaleExplorer.fbx.meta

@@ -5,7 +5,7 @@ ModelImporter:
   internalIDToNameTable: []
   externalObjects: {}
   materials:
-    materialImportMode: 0
+    materialImportMode: 2
     materialName: 0
     materialSearch: 1
     materialLocation: 1
@@ -52,7 +52,7 @@ ModelImporter:
     useFileUnits: 1
     keepQuads: 0
     weldVertices: 1
-    bakeAxisConversion: 0
+    bakeAxisConversion: 1
     preserveHierarchy: 0
     skinWeightsMode: 0
     maxBonesPerVertex: 4
@@ -67,7 +67,7 @@ ModelImporter:
     secondaryUVMinLightmapResolution: 40
     secondaryUVMinObjectScale: 1
     secondaryUVPackMargin: 4
-    useFileScale: 1
+    useFileScale: 0
     strictVertexDataChecks: 0
   tangentSpace:
     normalSmoothAngle: 60