[Feature] Add fileSizeInByte to top-level AssetResponseDto

I have searched the existing feature requests, both open and closed, to make sure this is not a duplicate request.

• Yes

The feature

Related to #31694, but instead of a new bulk endpoint, the fix is to expose fileSizeInByte at the top level of the response. Currently fileSizeInByte only lives inside exifInfo, so clients must request withExif: true just to get file sizes for directory listings. This forces downloading the full EXIF payload even when only filename + size are needed. For albums with thousands of assets, this makes paginated loads extremely slow

Adding fileSizeInByte as a top-level field would let withExif: false still return meaningful file sizes, significantly reducing API response size for listing operations

Platform

• Server
• Web
• Mobile