#651 Tenant API Key Management Workflows

Workflows for API key lifecycle. Workflows on _platform tenant: - _system.tenant.add_api_key - Create new API key, notify user - _system.tenant.rotate_api_key - Rotate key with grace period, notify Tools: - internal.tenant.create_api_key - internal.tenant.rotate_api_key - internal.tenant.revoke_api_key Parent: #639