CreateOrganizationLLMConfiguration

Creates an LLM provider configuration for an organization.

An organization can have one configuration per provider. Calling this RPC twice with the same (organization, provider) pair returns ALREADY_EXISTS; use UpdateOrganizationLLMConfiguration to rotate the key.

When api_key is set, the API key is encrypted before storage using organization-scoped encryption. When api_key is omitted or empty, the configuration uses the provider's backend global config key.