feat(01-01): implement LM Studio adapter with model discovery

- Created LMStudioAdapter class using lmstudio-python SDK
- Added context manager get_client() for safe client handling
- Implemented list_available_models() with size estimation
- Added load_model(), unload_model(), get_model_info() methods
- Created mock_lmstudio.py for graceful fallback when lmstudio not installed
- Included error handling for LM Studio not running and model loading failures
- Implemented Pattern 1 from research: Model Client Factory

src/models/mock_lmstudio.py

@@ -0,0 +1,34 @@
+"""Mock lmstudio module for testing without dependencies."""
+
+
+class Client:
+    """Mock LM Studio client."""
+
+    def close(self):
+        pass
+
+    class llm:
+        """Mock LLM interface."""
+
+        @staticmethod
+        def list_downloaded_models():
+            """Return empty list for testing."""
+            return []
+
+        @staticmethod
+        def model(model_key):
+            """Return mock model."""
+            return MockModel(model_key)
+
+
+class MockModel:
+    """Mock model for testing."""
+
+    def __init__(self, model_key):
+        self.model_key = model_key
+        self.display_name = model_key
+        self.context_length = 4096
+
+    def respond(self, prompt, max_tokens=100):
+        """Return mock response."""
+        return "mock response"