fix(model): match custom provider by active base url

tests/hermes_cli/test_custom_provider_model_switch.py

@@ -327,6 +327,118 @@ class TestCustomProviderModelSwitch:
         assert config["custom_providers"][0]["api_key"] == "${NEURALWATT_API_KEY}"
         assert "sk-live-neuralwatt-secret" not in saved
 
+    def test_bare_custom_current_provider_matches_env_base_url_before_first_fallback(
+        self, config_home, monkeypatch
+    ):
+        """`hermes model` must mark the custom provider matching model.base_url
+        as current instead of falling back to the first saved custom provider.
+
+        Regression: with ``model.provider: custom`` and multiple
+        ``custom_providers`` entries, the CLI resolved bare ``custom`` through
+        ``resolve_custom_provider()``, whose compatibility fallback returns the
+        first entry. A config with Cerebras first and NeuralWatt active then
+        showed Cerebras as current.
+        """
+        from hermes_cli.main import select_provider_and_model
+
+        config_path = config_home / "config.yaml"
+        config_path.write_text(
+            "model:\n"
+            "  default: kimi-k2.6-fast\n"
+            "  provider: custom\n"
+            "  base_url: ${NEURALWATT_API_BASE}\n"
+            "  api_key: ${NEURALWATT_API_KEY}\n"
+            "providers: {}\n"
+            "custom_providers:\n"
+            "- name: Cerebras.ai\n"
+            "  base_url: ${CEREBRAS_API_BASE}\n"
+            "  api_key: ${CEREBRAS_API_KEY}\n"
+            "  model: qwen-3-235b-a22b-instruct-2507\n"
+            "  models: []\n"
+            "- name: NeuralWatt\n"
+            "  base_url: ${NEURALWATT_API_BASE}\n"
+            "  api_key: ${NEURALWATT_API_KEY}\n"
+            "  model: kimi-k2.6-fast\n"
+            "  models: []\n"
+        )
+        monkeypatch.setenv("CEREBRAS_API_BASE", "https://api.cerebras.ai/v1")
+        monkeypatch.setenv("CEREBRAS_API_KEY", "sk-live-cerebras-secret")
+        monkeypatch.setenv("NEURALWATT_API_BASE", "https://api.neuralwatt.com/v1")
+        monkeypatch.setenv("NEURALWATT_API_KEY", "sk-live-neuralwatt-secret")
+
+        captured: dict = {}
+
+        def _capture_and_cancel(labels, default=0):
+            captured["labels"] = labels
+            captured["default"] = default
+            return len(labels) - 1  # Leave unchanged
+
+        with patch("hermes_cli.main._prompt_provider_choice",
+                   side_effect=_capture_and_cancel), \
+             patch("builtins.print"):
+            select_provider_and_model()
+
+        labels = captured["labels"]
+        default_label = labels[captured["default"]]
+        assert "NeuralWatt" in default_label
+        assert "currently active" in default_label
+        assert "Cerebras.ai" not in default_label
+        assert not any(
+            "Cerebras.ai" in label and "currently active" in label
+            for label in labels
+        )
+
+    def test_named_custom_provider_selection_preserves_base_url_env_ref(
+        self, config_home, monkeypatch
+    ):
+        """Selecting an env-backed custom provider should not expand its
+        ``base_url`` template into ``model.base_url`` on disk."""
+        import yaml
+        from hermes_cli.main import select_provider_and_model
+
+        config_path = config_home / "config.yaml"
+        config_path.write_text(
+            "model:\n"
+            "  default: old-model\n"
+            "  provider: openrouter\n"
+            "custom_providers:\n"
+            "- name: NeuralWatt\n"
+            "  base_url: ${NEURALWATT_API_BASE}\n"
+            "  api_key: ${NEURALWATT_API_KEY}\n"
+            "  model: qwen3.6-35b-fast\n"
+            "  models: []\n"
+        )
+        monkeypatch.setenv("NEURALWATT_API_BASE", "https://api.neuralwatt.com/v1")
+        monkeypatch.setenv("NEURALWATT_API_KEY", "sk-live-neuralwatt-secret")
+
+        def _pick_neuralwatt(labels, default=0):
+            for i, label in enumerate(labels):
+                if "NeuralWatt" in label:
+                    return i
+            raise AssertionError(
+                f"NeuralWatt entry missing from provider menu: {labels}"
+            )
+
+        with patch("hermes_cli.main._prompt_provider_choice",
+                   side_effect=_pick_neuralwatt), \
+             patch("hermes_cli.models.fetch_api_models",
+                   return_value=["qwen3.6-35b-fast"]) as mock_fetch, \
+             patch.dict("sys.modules", {"simple_term_menu": None}), \
+             patch("builtins.input", return_value="1"), \
+             patch("builtins.print"):
+            select_provider_and_model()
+
+        mock_fetch.assert_called_once()
+        probe_args, _ = mock_fetch.call_args
+        assert probe_args[1] == "https://api.neuralwatt.com/v1"
+
+        saved = config_path.read_text()
+        config = yaml.safe_load(saved) or {}
+        assert config["model"]["base_url"] == "${NEURALWATT_API_BASE}"
+        assert config["model"]["api_key"] == "${NEURALWATT_API_KEY}"
+        assert "https://api.neuralwatt.com/v1" not in saved
+        assert "sk-live-neuralwatt-secret" not in saved
+
     def test_key_env_providers_dict_entry_does_not_add_api_key(
         self, config_home, monkeypatch
     ):