Expo Paste Input Patch

expo-paste-input observes UITextView.textDidChangeNotification and treats any NSTextAttachment in the text view's attributedText as a pasted image. When it can't find a real image payload on an attachment, it falls back to image(forBounds:) and, failing that, to a drawHierarchy screenshot of the text view at the attachment's glyph rect.

iOS Dictation inserts its own NSTextAttachment (the shimmer/cursor indicator) into the text view during dictation. Those attachments don't carry real image data, so the fallbacks would fire — emitting a zoomed-in screenshot of the composer as if the user had pasted an image at the end of dictation.

This patch:

• Removes the image(forBounds:) and renderTextAttachment fallbacks in extractMediaPayload so the library only accepts attachments carrying a real payload (fileWrapper, contents, or image).
• Only sanitizes (deletes) attachment ranges that produced a payload, and skips the "unsupported" toast when an attachment has no payload. Unknown system attachments like the dictation placeholder are left alone rather than being ripped out from under iOS.