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>

office-translator-landing-page/components/ui/spinner.tsx

@@ -0,0 +1,16 @@
+import { Loader2Icon } from 'lucide-react'
+
+import { cn } from '@/lib/utils'
+
+function Spinner({ className, ...props }: React.ComponentProps<'svg'>) {
+  return (
+    <Loader2Icon
+      role="status"
+      aria-label="Loading"
+      className={cn('size-4 animate-spin', className)}
+      {...props}
+    />
+  )
+}
+
+export { Spinner }