[Bug]: Copy image fails for data URL images in the desktop app #23619

Area

apps/web

Steps to reproduce

1. In the desktop app, open an HTML render (html_render) that embeds an image as <img src="data:image/png;base64,...">.
2. Click the image to open it in the image viewer.
3. Right-click it and choose Copy image (or Save image).

Expected behavior

The image is copied to the clipboard (or saved).

Actual behavior

The action fails with "The file could not be fetched. The host may block browser access (CORS), or the connection may be unavailable." No request reaches the server.

readMediaBlob in apps/web/src/components/media/mediaContent.ts calls fetch(src) for every source. The desktop renderer's CSP (makeDesktopContentSecurityPolicy) leaves data: out of connect-src, so fetch on a data URL is blocked and rejects like a network error. apps/web/src/lib/previewAnnotation.ts already works around the same limit by decoding its data URL locally.

Impact

Minor bug or occasional failure

Version or commit

Desktop nightly 0.1.2-nightly.20261022.3512, server on the same Windows machine.

Environment

Windows 11, desktop app paired to a background server on the same machine.

Related

#21367 routes desktop Save through webContents.downloadURL, which also covers data: for Save. #23084 adds a server fallback for http(s) images on Copy. Neither covers Copy of a data: image.