Avatars/banners now resize to max 512px/1920px and convert to WebP before
upload (zero server cost). Chat image uploads generate an 800px-wide WebP
thumbnail via Sharp; the feed shows the thumbnail, click opens the full-res
original. Adds lazy loading to avatars. Federation-compatible: remote
instances without this feature fall back gracefully.
Wire react-easy-crop into CreateSpace so users can crop and zoom before
uploading a space icon. Adds reusable ImageCropModal component and
canvas crop utility for future use in space settings and avatar editing.
Jannis Braun