Legacy Login Endpoint Marked Deprecated

We marked POST /api/v1/login as deprecated in our OpenAPI documentation and added guidance recommending OAuth 2.0 for new integrations. OAuth 2.0 provides more secure, granular access without generating persistent API keys through the legacy login flow.

The annotation did not disable the endpoint or remove access from existing integrations. No sunset date or removal timeline has been set. Existing consumers can continue using the endpoint, while new integrations should use OAuth 2.0.