[VSCode] Strip invisible characters from prompts

Paste text

Text you paste stays visible in the prompt box, rather than collapsing to a placeholder as it does in the terminal. In sessions where Claude Code marks pasted text, Claude still sees a large paste as text you pasted rather than typed.

Claude Code also removes invisible Unicode characters from text you paste into the prompt box and from anything else you send:

• If a notice such as Removed 3 invisible characters from the pasted text appears when you paste, the text went in without those characters.
• If a notice about removed characters appears when you send, nothing was sent. The cleaned text is back in the prompt box. Send again to send the text as shown.