feat: homelab deployment - NPM + IONOS DNS + monitoring + NAS backup

- Restructured docker-compose for Nginx Proxy Manager (no custom nginx)
- Added domain wordly.art configuration
- Added Prometheus + Grafana monitoring stack with pre-configured dashboards
- Added PostgreSQL backup script to NAS (daily/weekly/monthly rotation)
- Added alert rules for backend, system, and Docker metrics
- Updated deployment guide for NPM + IONOS DNS homelab setup
- Added marketing plan document
- PDF translator and watermark support
- Enhanced middleware, routes, and translator modules

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/app/dashboard/DashboardHeader.tsx

@@ -7,7 +7,6 @@ import {
   Languages, 
   Menu, 
   X, 
-  ChevronLeft,
   LogOut
 } from 'lucide-react';
 import { cn } from '@/lib/utils';
@@ -144,13 +143,6 @@ export function DashboardHeader() {
               <LogOut className="size-4 shrink-0" />
               {t('dashboard.sidebar.signOut')}
             </button>
-            <Link
-              href="/"
-              className="flex items-center gap-3 rounded-lg px-3 py-2 text-sm font-medium text-muted-foreground hover:bg-secondary/60 hover:text-foreground"
-            >
-              <ChevronLeft className="size-4 shrink-0" />
-              {t('dashboard.sidebar.backHome')}
-            </Link>
           </nav>
         </div>
       )}