Incorrect paste behavior, paste causes highlight failure and style errors

[Innei]

Since this is a contentable element, there is no processing when pasting rich text, and it should only paste plain text.

CleanShot.2024-11-10.at.2.15.22.mp4

[KazariEX]

The original intention of doing this is to make some rich text in the code work well, because not all browsers support contenteditable="plaintext-only". I'm not sure if manually support this will introduce too much rich text processing code into the library.