Add user defined system message

internal/llm/llm_test.go

@@ -67,11 +67,11 @@ func TestConfigValidate(t *testing.T) {
 		{
 			name: "valid full config",
 			cfg: Config{
-				Key:          "sk-test-key",
-				Model:        "test-model",
-				SystemPrompt: "You are a helpful assistant.",
-				Timeout:      "30m",
-				URL:          "http://localhost:8080",
+				Key:           "sk-test-key",
+				Model:         "test-model",
+				SystemMessage: "You are a helpful assistant.",
+				Timeout:       "30m",
+				URL:           "http://localhost:8080",
 			},
 			wantErr: false,
 		},
@@ -121,11 +121,11 @@ func TestNewClient(t *testing.T) {
 		{
 			name: "valid config with all fields",
 			cfg: Config{
-				Key:          "test-key",
-				Model:        "test-model",
-				SystemPrompt: "Test prompt",
-				Timeout:      "5m",
-				URL:          "http://localhost:8080",
+				Key:           "test-key",
+				Model:         "test-model",
+				SystemMessage: "Test message",
+				Timeout:       "5m",
+				URL:           "http://localhost:8080",
 			},
 			wantErr: false,
 		},