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/document-indexes.test.ts

@@ -22,7 +22,10 @@ const document: ImageDocument = {
       locked: false,
       layers: [
         raster("mask", "Mask", "asset-mask"),
-        { ...raster("target", "Target", "asset-target", { x: 10, y: 20 }, { x: 0.5, y: 0.5 }), clippingMask: { maskLayerId: "mask" } },
+        {
+          ...raster("target", "Target", "asset-target", { x: 10, y: 20 }, { x: 0.5, y: 0.5 }),
+          layerMask: { kind: "raster", maskLayerId: "mask", enabled: true, inverted: false },
+        },
         group("group", "Group", [
           raster("nested-mask", "Nested Mask", "asset-mask"),
           { ...raster("nested-target", "Nested Target", "asset-nested", { x: 80, y: 10 }, { x: 2, y: 3 }), clippingMask: { maskLayerId: "nested-mask" } },