Pressing ⌘C on macOS does not copy the selected text

[unikitty37]

Pressing ⌘C in Ghostty on macOS does not copy the text. This is a standard macOS shortcut, and it should work. (⌘V works fine for pasting.)

Even selecting Edit > Copy from the menu bar does not copy the selected text, but leaves the pasteboard with its previous contents. If I try the same in iTerm 2, I get this message:

and pressing ⌥T does indeed allow the selection to be copied. However, once I've done this, then there is no way to turn mouse selection back on again and I can no longer click on things. Additionally, I need this to work in Ghostty, where there is no such option.

The docs don't mention how I can configure the Command or Option keys, and mention installing Textual, but brew info textual shows it to be an IRC client:

 brew info textual
==> textual: 7.2.6,65222a260 (auto_updates)
https://www.codeux.com/textual/
Not installed
From: https://github.com/Homebrew/homebrew-cask/blob/HEAD/Casks/t/textual.rb
==> Name
Textual
==> Description
Application for interacting with Internet Relay Chat (IRC) chatrooms
==> Artifacts
Textual.app (App)
==> Downloading https://formulae.brew.sh/api/cask/textual.json
==> Analytics
install: 93 (30 days), 226 (90 days), 1,029 (365 days)

It would help if the "install Textual" text linked to instructions on how to do this — and, if it's a Python library, preferably instructions that don't assume everybody's a Pythonista, like so many Python libraries do :)

Please could Posting support assigning the standard macOS keyboard shortcut ⌘C to "copy"?