Function copy_plain_text_to_clipboard 

pub fn copy_plain_text_to_clipboard(text: &str) -> Result<(), String>

What: Copy plain text to the system clipboard without extra suffixes.

Inputs:

• text: Exact bytes to place on the clipboard.

Output:

• Ok(()) when wl-copy or xclip accepted stdin.

Errors

• Returns Err with install guidance when neither clipboard tool could be spawned.

Details:

• Prefers wl-copy when WAYLAND_DISPLAY is set, otherwise tries xclip.
• Does not invoke a shell; uses Command argument lists only.