File API drag and drop does not work in contenteditable

Phenomenon

When trying to drag and drop files into a contenteditable element, the File API may not work as expected. File drop events may not fire, or file content may not be accessible.

Reproduction example

1. Create a contenteditable div.
2. Try to drag a file from the file system into the contenteditable.
3. Listen for drop events and try to read file content.
4. Observe whether files can be dropped and accessed.

Observed behavior

• In Safari on macOS, file drag and drop may not work in contenteditable.
• Drop events may not fire for files.
• File content may not be accessible.
• The default paste behavior may interfere.

Expected behavior

• File drag and drop should work in contenteditable.
• Drop events should fire correctly.
• File content should be accessible via File API.