A VS Code style editor by default

What changed

• The assessment Editor window now looks like VS Code by default, with quick file open, a browser bar on Preview, and a Ports tab.
• The start page states each question's real AI rules and the skills the report scores. Participants are told what is really recorded, and the webcam page is shorter and plainer.
• No AI questions get no AI anywhere on the page. Question tabs say started, not finished, for questions with work on them.