When dragging the floating screenshot preview into a room, iOS hands us
a provider whose `suggestedName` is e.g. `Screenshot 2026-05-22 at
14.49.40`. `NSString.pathExtension` returns `"40"`, so the previous
`!pathExtension.isEmpty` check treated the timestamp's trailing segment
as a real extension. The file got written without `.jpg`/`.png`, and the
`MediaUploadingPreprocessor` then fell back to `application/octet-stream`
which is why screenshots showed up as a "data" tile.
Mauro
Doug
Quentin Gliech