feat(settings): add SMTP admin configuration

backend/hermes/app/main.py

@@ -17,6 +17,7 @@ from app.api.knowledge import router as knowledge_router
 from app.api.permissions import router as permissions_router
 from app.api.repairs import router as repairs_router
 from app.api.roles import router as roles_router
+from app.api.system_settings import router as system_settings_router
 from app.api.users import router as users_router
 from app.db.database import SessionLocal
 from app.db.health import check_database
@@ -42,6 +43,7 @@ app.include_router(customers_router)
 app.include_router(knowledge_router)
 app.include_router(repairs_router)
 app.include_router(dashboard_router)
+app.include_router(system_settings_router)
 
 logger = logging.getLogger(__name__)