The provider wizard offered "Sign in with OAuth" for xAI and Hugging Face, but
clicking did nothing: the login managers were built without an env, so the preset
opt-in (ZERO_OAUTH_ALLOW_PRESETS) read as unset, ResolveConfig errored before any
browser step, and the error was never rendered on the provider list. Only ChatGPT
worked, because its login path force-enables presets.
Add ManagerOptions.AllowPresets, which layers the opt-in onto the manager env
(snapshotting the process environment so ZERO_OAUTH_<NAME>_* overrides survive
envValue's hermetic-map rule) without the operator exporting the flag. Set it on
every user-initiated OAuth manager: the wizard loopback login, the device-code
prepare/complete, the post-login token refresh, the runtime resolver that
authenticates model calls, and `zero auth login`. This fixes xAI end to end (it
ships a public client_id, so the browser now opens).
Also surface a failed OAuth attempt on the provider list (renderProviderStep) so
the click is no longer a silent no-op, with a Hugging Face hint pointing at app
registration + ZERO_OAUTH_HUGGINGFACE_CLIENT_ID (HF ships no public client_id, so
it still requires that one env var by design).
Vasanth T
c4c14d62d4