Release 2.21.0: non-destructive media and scoped player sync

docs/user/guide-web.md

@@ -139,7 +139,7 @@ Use **Edit default content** to set a region's starting content with the same ty
 The available region types cover fixed content, uploaded media, live data, and external content:
 
 - **Text:** rich text content with font family, font size, font colour, and normal editorial formatting. Use it for headings, labels, paragraphs, and other copy that editors change per slide.
-- **Image:** an uploaded image in the media library. The editor supports PNG, JPG, GIF, WebP, and SVG images, with cropping to the region ratio when needed.
+- **Image:** a reusable image in the media library. The editor supports PNG, JPG, GIF, WebP, and SVG images, with optional crop, rotate, flip, and zoom tools that leave the original unchanged.
 - **Video:** an uploaded MP4, WebM, or Ogg video. Videos preview in the region and loop during playback.
 - **HTML:** HTML content rendered inside a sandboxed preview. Use it for controlled custom markup when an ordinary text region cannot express the design.
 - **Webpage:** a URL displayed in an embedded webpage region. Use it for a page that should be shown inside the slide, and verify that the destination permits embedding.
@@ -318,7 +318,7 @@ See the [Data Sources guide](guide-data-sources.md) for supported source types,
 
 ## Media
 
-Media is added where it is needed in a template or slide. Image and video regions provide their own upload controls, while template backgrounds are uploaded from the template options. An upload in one slide or template is not automatically a reusable selection in every other slide, so add the file to each region or template where it is required.
+Media is added where it is needed in a template or slide, or directly through the Media Library. Image and video regions provide their own upload controls, while template backgrounds are uploaded from the template options. Use the shared media picker to reuse an uploaded asset in another region or template without uploading another copy.
 
 ### Images
 
@@ -330,7 +330,13 @@ When adding an image:
 - Keep important subjects away from the edges when the region may crop the image.
 - Check the crop and scaling in the slide preview before publishing.
 - Use a transparent PNG or SVG when the design needs the background to show through.
-- Remember that animated image formats may be altered if they are cropped or transformed.
+- Uploads retain the full original, including SVG vectors and animated images. Applying a crop creates a separate image copy for that placement; SVG and animated GIF crops become PNGs, while the original vectors or animation remain available.
+
+Images are uploaded in full. The crop editor opens automatically after an image upload completes or an existing image is selected from the library. It offers a crop box, ratio presets (including **Region**), rotation, flip, and zoom controls. Choose **Edit crop** on an image region to reopen it later. **Apply crop** remembers the original and crop settings; applying an untouched full-image selection keeps it uncropped. **Cancel** discards a newly selected image and cleans up a new upload if nothing saved uses it. Existing library images are not deleted. When reopening an already applied image, **Cancel** leaves that previous selection unchanged. Save the slide to retain the changes. Different slides can crop the same original independently. Previously cropped files remain usable, but their missing content can only be recovered by uploading the original again.
+
+Playback images fit the region's pixel dimensions and slide canvas, preserving aspect ratio without enlarging small images. An uncropped original that already fits is used directly, without creating a duplicate file. Larger originals and cropped images get appropriately sized playback copies. Uncropped GIF and WebP copies retain their animation. Saving a larger region or changing its shared template regenerates the copy from the full original when needed. The original file remains unchanged.
+
+Uploaded media synchronization is scoped to each player's client screen assignments and playlists, including last-known assignments for offline clients. Players receive the playback image, not its editing original, unless the original is itself the playback file. This works for direct players and players reached through the bridge. Obsolete player copies are removed when no longer needed by that player; files shared with web storage are retained while the web still needs them. Managed fonts and weather icons keep their separate synchronization rules.
 
 ### Videos