test(config): cover LM Studio nullable api key

tests/cli/test_commands.py

@@ -257,6 +257,28 @@ def test_config_accepts_camel_case_explicit_provider_name_for_coding_plan():
     assert config.get_api_base() == "https://ark.cn-beijing.volces.com/api/coding/v3"
 
 
+def test_config_accepts_lm_studio_without_api_key_and_uses_default_localhost_api_base():
+    config = Config.model_validate(
+        {
+            "agents": {
+                "defaults": {
+                    "provider": "lm_studio",
+                    "model": "local-model",
+                }
+            },
+            "providers": {
+                "lmStudio": {
+                    "apiKey": None,
+                }
+            },
+        }
+    )
+
+    assert config.get_provider_name() == "lm_studio"
+    assert config.get_api_key() is None
+    assert config.get_api_base() == "http://localhost:1234/v1"
+
+
 def test_find_by_name_accepts_camel_case_and_hyphen_aliases():
     assert find_by_name("volcengineCodingPlan") is not None
     assert find_by_name("volcengineCodingPlan").name == "volcengine_coding_plan"