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/translate/useTranslationSubmit.ts

@@ -8,8 +8,7 @@ import type {
   TranslationSubmitResponse,
   TranslationStatusResponse 
 } from './types';
-
-const API_BASE = process.env.NEXT_PUBLIC_API_URL || 'http://localhost:8000';
+import { API_BASE } from '@/lib/config';
 const POLLING_INTERVAL_MS = 2000;
 const MAX_POLLING_FAILURES = 3;
 
@@ -58,6 +57,7 @@ export function useTranslationSubmit(): UseTranslationSubmitReturn {
       if (!response.ok) {
         if (response.status === 404) {
           stopPolling();
+          setIsSubmitting(false);
           setStatus('failed');
           setError('Translation job not found');
           return;
@@ -81,6 +81,7 @@ export function useTranslationSubmit(): UseTranslationSubmitReturn {
 
       if (job.status === 'completed' || job.status === 'failed') {
         stopPolling();
+        setIsSubmitting(false);
         if (job.status === 'failed') {
           setError(job.error_message || 'Translation failed');
         }
@@ -92,6 +93,7 @@ export function useTranslationSubmit(): UseTranslationSubmitReturn {
       
       if (pollingFailuresRef.current >= MAX_POLLING_FAILURES) {
         stopPolling();
+        setIsSubmitting(false);
         setStatus('failed');
         setError('Lost connection to translation service. Please check your internet connection and try again.');
       }