feat: enhance layer mask handling and opacity management

- Introduced `getLayerMask` utility to streamline layer mask retrieval.
- Updated layer rendering logic to incorporate layer masks and opacity adjustments.
- Added functionality to prevent dropping a group into its descendants.
- Enhanced image texture rendering to support opacity parameters across various rendering functions.
- Implemented group layer bounds application for better scaling and positioning.
- Added tests to ensure correct behavior when handling layer masks and group layers.
- Created new types for asset generation provenance to track generated assets more effectively.

editor/initial-state.ts

@@ -15,6 +15,7 @@ export const initialEditorState: EditorState = {
   generation: {
     candidates: [],
     selectedCandidateId: undefined,
+    compareMode: "result",
   },
   transformSession: undefined,
   maskEdit: undefined,