I find the new headline to be much more clear. Perhaps because I imagined Claude to already be able to "edit and create files" via Claude Code; the server-side container is the key difference.

Yeah, that was my initial confusion: Claude can already create files using both the Artifacts feature and Claude Code, so "Claude can now create and edit files" didn't sound like a new feature to me. Finding out this was actually a full-blown sandboxed container environment with both Python and Node.js was far more interesting.