feat: adaptive progressive image loading for photo viewer (#26636)

* feat(web): adaptive progressive image loading for photo viewer

Replace ImageManager with a new AdaptiveImageLoader that progressively
loads images through quality tiers (thumbnail → preview → original).

New components and utilities:
- AdaptiveImage: layered image renderer with thumbhash, thumbnail,
  preview, and original layers with visibility managed by load state
- AdaptiveImageLoader: state machine driving the quality progression
  with per-quality callbacks and error handling
- ImageLayer/Image: low-level image elements with load/error lifecycle
- PreloadManager: preloads adjacent assets for instant navigation
- AlphaBackground/DelayedLoadingSpinner: loading state UI

Zoom is handled via a derived CSS transform applied to the content
wrapper in AdaptiveImage, with the zoom library (zoomTarget: null)
only tracking state without manipulating the DOM directly.

Also adds scaleToCover to container-utils and getAssetUrls to utils.

* fix: don't partially render images in firefox

* add passive loading indicator to asset-viewer

---------

Co-authored-by: Alex <alex.tran1502@gmail.com>

web/src/lib/utils.ts

@@ -186,6 +186,14 @@ export const getAssetUrl = ({
   return getAssetMediaUrl({ id, size, cacheKey });
 };
 
+export function getAssetUrls(asset: AssetResponseDto, sharedLink?: SharedLinkResponseDto) {
+  return {
+    thumbnail: getAssetMediaUrl({ id: asset.id, cacheKey: asset.thumbhash, size: AssetMediaSize.Thumbnail }),
+    preview: getAssetUrl({ asset, sharedLink })!,
+    original: getAssetUrl({ asset, sharedLink, forceOriginal: true })!,
+  };
+}
+
 const forceUseOriginal = (asset: AssetResponseDto) => {
   return asset.type === AssetTypeEnum.Image && asset.duration && !asset.duration.includes('0:00:00.000');
 };