fix(sdk): don't log out Codex/OCA users when token refresh fails transiently (#13565)

* fix(sdk): don't log out Codex/OCA users when token refresh fails transiently

Port the cline-provider refresh semantics to openai-codex and oca:
a transient refresh failure (network error, timeout, server 5xx) with an
already-expired access token now rethrows instead of returning null.
A null return means the refresh token was REJECTED and re-auth is
required; treating an outage blip as a rejection is what turned it into
a forced 'openai-codex requires re-authentication.' task stop while the
settings UI still showed the user as signed in.

Both providers also emit user.auth_refresh_soft_failure telemetry on
transient failures (the 'prevented logout' counter the cline provider
already has) and attach status/errorCode details to the genuine
invalid_grant logout event.

* refactor: collapse duplicate soft-failure telemetry branches and test

Review feedback: compute tokenExpired once and emit the soft-failure
event once in both providers, then return current credentials or
rethrow. Fold the codex soft-failure telemetry assertions into the
existing still-usable-token test instead of a near-duplicate case.