feat(editor): multi-select objects, time-of-day lighting, WOT loading

- Multi-select: Ctrl+Shift+Click adds objects to selection, transforms
  (move/rotate/scale/delete) operate on all selected objects at once
- Time-of-day slider (0-24h) with automatic sun angle, light color,
  ambient, fog, and sky color transitions (dawn/day/dusk/night)
- View > Sky/Lighting menu: color pickers for light/ambient/fog, fog
  distance sliders, preset buttons (Dawn/Noon/Dusk/Night)
- loadADT prefers WOT/WHM open format from custom_zones/output dirs
- Selection count display when multiple objects selected
- setSkyPreset now delegates to setTimeOfDay for consistency

tools/editor/editor_app.hpp

@@ -53,6 +53,7 @@ public:
     NpcPresets& getNpcPresets() { return npcPresets_; }
     QuestEditor& getQuestEditor() { return questEditor_; }
     AssetBrowser& getAssetBrowser() { return assetBrowser_; }
+    EditorViewport& getViewport() { return viewport_; }
     rendering::TerrainRenderer* getTerrainRenderer();
     rendering::M2Renderer* getM2Renderer() { return viewport_.getM2Renderer(); }
     pipeline::AssetManager* getAssetManager() { return assetManager_.get(); }