Fixes the Photon phantom-providers regression from #4247 (v0.51.461): the
credential-pool detection loop added every auth.json credential_pool key to
detected_providers without checking it names a model provider, so the Photon
iMessage plugin's photon/photon_project/photon_user messaging credentials each
rendered as a phantom provider carrying the full auto-detected model catalog
(251 models on the reporter's machine).
Gated on a new _is_known_model_provider() check (custom:* slug, static
_PROVIDER_DISPLAY/_PROVIDER_MODELS entry, or registered model-provider plugin)
on both the load_pool and raw-dict fallback paths; the group-builder's generic
fallback no longer paints an unrecognized id with the global catalog. Real
pool-keyed providers (copilot, aliased google->gemini) still surface.
Integrates the stronger of two independent same-fix PRs — #4330's implementation
(thorough docstring, try/except-hardened plugin check, preserved #1881 comment,
defensive else branch) + its 8-case test that mocks at the WebUI boundary
(stubs hermes_cli, never imports the bundled agent package that's absent in CI,
exercises both the load_pool and ImportError raw-dict paths) — over #4329's
2-case test. Both rodboev (#4329) and the maintainer agent (#4330) independently
found and fixed the same regression.
Reported by Nic.
Co-authored-by: rodboev <rodboev@users.noreply.github.com>
