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>

opencode.json

@@ -0,0 +1,15 @@
+{
+  "mcp": {
+    "agentation": {
+      "type": "local",
+      "command": [
+        "npx",
+        "-y",
+        "agentation-mcp",
+        "server"
+      ],
+      "enabled": true,
+      "environment": {}
+    }
+  }
+}