fix: QA audit — lint cleanup, i18n fixes, module visibility, sidebar UX

- Fix 97 lint errors → 0 (unused imports, params, variables across 40+ files)
- Fix i18n key format: colon → dot notation for next-intl compatibility
- Add missing i18n keys (routes.application, routes.home, confirm)
- Fix module visibility: sidebar now respects per-account DB features
- Fix inject function: use dot-notation keys, add collapsed:true defaults
- Fix ConfirmDialog: use useTranslations instead of hardcoded German defaults
- Fix events page: replace placeholder 'Beschreibung' with proper description
- Fix Dockerfile: add NEXT_PUBLIC_CI ARG for Docker builds
- Collapse secondary sidebar sections by default for cleaner UX

apps/web/app/[locale]/home/[account]/site-builder/page.tsx

@@ -17,7 +17,7 @@ import { createSiteBuilderApi } from '@kit/site-builder/api';
 import { getSupabaseServerClient } from '@kit/supabase/server-client';
 import { Badge } from '@kit/ui/badge';
 import { Button } from '@kit/ui/button';
-import { Card, CardContent, CardHeader, CardTitle } from '@kit/ui/card';
+import { Card, CardContent } from '@kit/ui/card';
 import { cn } from '@kit/ui/utils';
 
 import { AccountNotFound } from '~/components/account-not-found';