Redesign B3 bordeaux + finish lab-page rework

- Lab page is now read-only with a settings screen for levels/variants;
  variant issuance moved to a large modal on the group page (assign-fragment).
- Header: bordeaux logo and 2px accent underline, bordeaux login/logout/theme
  buttons; smaller radii across the UI; filled secondary/danger buttons.
- Includes prior agent work (login backoff, no-cache pages, API timeouts,
  content tweaks) and fixes (variant usage Map.values, import order).
- Bump static asset version to v=9.

web/src/main/resources/static/js/mdeditor.js

@@ -113,7 +113,8 @@
     };
 
     document.addEventListener('input', function (event) {
-        if (event.target && event.target.id === 'article-body') dirty = true;
+        var id = event.target && event.target.id;
+        if (id === 'article-body' || id === 'article-title') dirty = true;
     });
 
     /* Сохранение — это осознанный уход со страницы, подтверждение не нужно */