fix(editor): NPC ghost preview, scale control, frame sync for M2 rendering

- Ghost preview now shows in NPC mode (follows cursor with creature model)
- Added scale field to CreatureSpawn (default 1.0, slider 0.5-10x)
- NPC instances render at their configured scale
- Scale included in JSON save format
- M2Renderer::update() now runs AFTER beginFrame() so getCurrentFrame()
  returns the correct frame index — fixes instance SSBO mismatch that
  caused draws=0 despite loaded models

tools/editor/editor_ui.cpp

@@ -458,6 +458,8 @@ void EditorUI::renderNpcPanel(EditorApp& app) {
             if (ImGui::InputText("Name##tmpl", nameBuf, sizeof(nameBuf)))
                 tmpl.name = nameBuf;
 
+            ImGui::SliderFloat("Scale", &tmpl.scale, 0.5f, 10.0f, "%.1f");
+
             int lvl = tmpl.level;
             if (ImGui::SliderInt("Level", &lvl, 1, 83)) {
                 tmpl.level = lvl;