feat: production deployment - full update with providers, admin, glossaries, pricing, tests

Major changes across backend, frontend, infrastructure:
- Provider system with model selection (Google, DeepL, OpenAI, Ollama, Google Cloud)
- Admin panel: user management, pricing, settings
- Glossary system with CSV import/export
- Subscription and tier quota management
- Security hardening (rate limiting, API key auth, path traversal fixes)
- Docker compose for dev, prod, and IONOS deployment
- Alembic migrations for new tables
- Frontend: dashboard, pricing page, landing page, i18n (en/fr)
- Test suite and verification scripts

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/app/dashboard/constants.ts

@@ -1,23 +1,23 @@
-import { LayoutDashboard, FileText, Key, BookText, type LucideIcon } from 'lucide-react';
+import { FileText, Key, BookText, User, type LucideIcon } from 'lucide-react';
 
 export interface NavItem {
-  label: string;
+  labelKey: string;
   href: string;
   icon: LucideIcon;
   proOnly?: boolean;
 }
 
 export const baseNavItems: NavItem[] = [
-  { label: 'Overview', href: '/dashboard', icon: LayoutDashboard },
-  { label: 'Translate', href: '/dashboard/translate', icon: FileText },
-  { label: 'API Keys', href: '/dashboard/api-keys', icon: Key },
+  { labelKey: 'dashboard.nav.translate', href: '/dashboard/translate', icon: FileText },
+  { labelKey: 'dashboard.nav.profile', href: '/dashboard/profile', icon: User },
+  { labelKey: 'dashboard.nav.apiKeys', href: '/dashboard/api-keys', icon: Key },
 ];
 
-export const proNavItem: NavItem = { 
-  label: 'Glossaries', 
-  href: '/dashboard/glossaries', 
+export const proNavItem: NavItem = {
+  labelKey: 'dashboard.nav.glossaries',
+  href: '/dashboard/glossaries',
   icon: BookText,
-  proOnly: true 
+  proOnly: true,
 };
 
 export function getNavItems(isPro: boolean): NavItem[] {