Support custom OIDC provider for user system (like Authenlia, Keycloak)

### Feature Idea

Now ComfyUI has its own user system and it support github/google account login.

However for advance users, they have their own SSO solution like Authenlia or Keycloak or some other custom OIDC providers.

Could ComfyUI applies the well known endpoint or setup manually for OIDC idP, so that users can login with their own SSO solutions?

### Existing Solutions

Currently besides Comfy account, users can use github/google account, which are not selfhosted.

### Other

_No response_