Generates a self-contained HTML warning page shown when a test run completes with 0 registered QUnit tests. Styled to match the QUnit HTML reporter, with an amber banner instead of red. Includes the same WebSocket reconnect script as buildErrorHTML so the page reloads on the next successful build.

import * as WebServer from './web-server.ts';

const html = WebServer.buildNoTestsHTML(['/proj/test/empty-test.ts']);
html.includes('0 QUnit tests were registered'); // true — lists the bundled files verbatim