How do I copy the unsent prompt text from Claude Code's input buffer to the clipboard with keyboard shortcut(s) only?

A Claude Code user running Ubuntu 22.04.4 LTS in Visual Studio Code for the Web seeks a keyboard-only method to copy unsent prompt text from the input buffer to the system clipboard for purposes such as saving templates or sharing content. The user reports that Ctrl+G, which functions on Windows PowerShell, opens a directory picker instead on their Linux system.