Tests (``tests/hermes_cli/test_auth_manual_paste.py``):
* 9 parametrised + scalar cases for ``_is_remote_session`` covering
the new Cloud Shell / Codespaces / Gitpod / Replit / StackBlitz
env vars (plus the existing SSH ones).
* 9 cases for ``_parse_pasted_callback`` covering every paste form
(full URL, https URL with extra params, bare ``?code=...``, bare
``code=...`` fragment, bare opaque value, error+description,
empty, whitespace-only, malformed URL).
* 3 cases for ``_prompt_manual_callback_paste`` (happy path, EOF,
Ctrl-C).
* 3 end-to-end ``_xai_oauth_loopback_login(manual_paste=True)``
cases: the HTTP server MUST NOT be started (asserted via a
callable that raises if invoked), wrong state still rejected
with ``xai_state_mismatch`` (no CSRF bypass), and empty paste
surfaces ``xai_code_missing``.
* SSH-hint mention test ensures the ``--manual-paste`` instruction
is printed in the remote-session hint.
Docs:
* ``oauth-over-ssh.md`` — new "Browser-only remote (Cloud Shell /
Codespaces / EC2 Instance Connect)" section with the
``--manual-paste`` recipe, plus a TL;DR note for the new flag.
* ``xai-grok-oauth.md`` — short subsection pointing at the same
recipe and the OAuth-over-SSH guide anchor.
