fix(cli): validate user-defined providers consistently

tests/hermes_cli/test_setup.py

@@ -339,6 +339,41 @@ def test_select_provider_and_model_warns_if_named_custom_provider_disappears(
     assert "selected saved custom provider is no longer available" in out
 
 
+def test_select_provider_and_model_accepts_named_provider_from_providers_section(
+    tmp_path, monkeypatch, capsys
+):
+    monkeypatch.setenv("HERMES_HOME", str(tmp_path))
+    _clear_provider_env(monkeypatch)
+
+    cfg = load_config()
+    cfg["model"] = {
+        "provider": "volcengine-plan",
+        "default": "doubao-seed-2.0-code",
+    }
+    cfg["providers"] = {
+        "volcengine-plan": {
+            "name": "volcengine-plan",
+            "base_url": "https://ark.cn-beijing.volces.com/api/coding/v3",
+            "default_model": "doubao-seed-2.0-code",
+            "models": {"doubao-seed-2.0-code": {}},
+        }
+    }
+    save_config(cfg)
+
+    monkeypatch.setattr(
+        "hermes_cli.main._prompt_provider_choice",
+        lambda choices, default=0: len(choices) - 1,
+    )
+
+    from hermes_cli.main import select_provider_and_model
+
+    select_provider_and_model()
+
+    out = capsys.readouterr().out
+    assert "Warning: Unknown provider 'volcengine-plan'" not in out
+    assert "Active provider:  volcengine-plan" in out
+
+
 def test_codex_setup_uses_runtime_access_token_for_live_model_list(tmp_path, monkeypatch):
     """Codex model list fetching uses the runtime access token."""
     monkeypatch.setenv("HERMES_HOME", str(tmp_path))