fix(editor): call M2Renderer::prepareRender to allocate mega bone slots before render

Without prepareRender(), animated NPC creature instances had megaBoneOffset=0
which caused the render loop to skip them (filtered out at the bones check).
This is why all loaded NPC M2s produced 0 draw calls despite valid GPU buffers,
material sets, and instance creation. Matches the main game's render flow.

tools/editor/editor_viewport.cpp

@@ -650,6 +650,7 @@ void EditorViewport::render(VkCommandBuffer cmd) {
                         m2Renderer_->getInstanceCount(), " instances, ",
                         m2Renderer_->getDrawCallCount(), " draws");
         }
+        m2Renderer_->prepareRender(frame, *camera_);
         m2Renderer_->render(cmd, perFrameSet, *camera_);
     }
     if (wmoRenderer_)