fix(model-picker): show exhausted-pool providers in interactive /model picker (#66584)

Salvages #66257 by @oppih (CI attribution check blocked the external
branch from merging).

When a provider's credential pool has entries but all are temporarily
rate-limited (exhausted), list_authenticated_providers() excluded the
provider from the interactive /model picker. Rate limits are per-model
for many providers (e.g. Google Gemini), so an exhausted key for
model-A may still work for model-B — the user should still be able to
select a different model under the same provider.

Adds a for_picker flag to list_authenticated_providers() that relaxes
the credential-pool availability check for the picker path only, falling
back to pool.has_credentials() when the pool has entries but none are
currently available. The runtime resolution path
(get_authenticated_provider_slugs) is unchanged, preserving the #45759
invariant that exhausted pools do not count as authenticated.

Co-authored-by: oppih <oppih@users.noreply.github.com>

hermes_cli/model_switch.py

@@ -1496,6 +1496,7 @@ def list_authenticated_providers(
     refresh: bool = False,
     probe_custom_providers: bool = True,
     probe_current_custom_provider: bool = False,
+    for_picker: bool = False,
 ) -> List[dict]:
     """Detect which providers have credentials and list their curated models.
 
@@ -1843,6 +1844,20 @@ def list_authenticated_providers(
             try:
                 if _credential_pool_is_usable(hermes_slug):
                     has_creds = True
+                elif for_picker:
+                    # For the interactive /model picker, also show providers
+                    # whose credential pool has entries but all are temporarily
+                    # rate-limited.  Rate limits are per-model for many
+                    # providers (e.g. Google Gemini) — switching to a different
+                    # model under the same provider may work even when all keys
+                    # are in cooldown.
+                    try:
+                        from agent.credential_pool import load_pool
+                        _pool = load_pool(hermes_slug)
+                        if _pool.has_credentials():
+                            has_creds = True
+                    except Exception:
+                        pass
             except Exception as exc:
                 logger.debug("Credential pool check failed for %s: %s", hermes_slug, exc)
         # Fallback: check external credential files directly.
@@ -2488,6 +2503,7 @@ def list_picker_providers(
         custom_providers=custom_providers,
         max_models=max_models,
         current_model=current_model,
+        for_picker=True,
     )
     if include_moa:
         providers = _prepend_moa_picker_provider(providers, current_provider=current_provider)

tests/hermes_cli/test_authenticated_providers_exhausted_pool.py

@@ -95,3 +95,22 @@ def test_opaque_legacy_pool_value_stays_visible(monkeypatch):
     )
 
     assert _credential_pool_is_usable("opencode-go", raw_pool_present=True)
+
+
+def test_picker_shows_exhausted_pool_provider(monkeypatch):
+    """The interactive picker must include providers whose credential pool
+    entries are all exhausted, so the user can still switch to a different
+    model under the same provider."""
+    from hermes_cli.model_switch import list_picker_providers
+
+    _patch_opencode_pool(monkeypatch, available=False)
+    providers = list_picker_providers(
+        current_provider="alibaba",
+        user_providers={},
+        custom_providers=[],
+    )
+    slugs = [p["slug"] for p in providers]
+    assert "opencode-go" in slugs, (
+        "Picker must show exhausted-pool providers so the user can select "
+        "a different model under the same provider"
+    )