Native dark theme for the console

It would be great to have a first-class dark theme across the console and the editor. Plenty of us are in the tool well past nine in the evening, and a darker surface would cut eye strain and keep attention on the work.

A few things worth covering:

• Manual toggle between light and dark
• Follow the operating system appearance
• Consistent dark styling for dialogs, tables and editor chrome
• Higher-contrast option for low-vision users 😄