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>

routes/deps.py

@@ -1,6 +1,7 @@
 """
 Shared authentication dependencies for routes.
 Story 3.9: Extracted from api_key_routes.py and glossary_routes.py
+Story 6.4: Bind user_id to structlog context when user is resolved.
 """
 
 import logging
@@ -86,6 +87,11 @@ def require_auth(
             },
         )
 
+    try:
+        from core.logging import bind_request_context
+        bind_request_context(user_id=str(getattr(user, "id", user)))
+    except Exception:
+        pass
     return user