feat: add OpenAPI enable flag

Co-authored-by: aider (openrouter/moonshotai/kimi-k2) <aider@aider.chat>

Author: Slach

pkg/config/config_test.go

@@ -47,6 +47,7 @@ logging:
 		require.Equal(t, 8080, cfg.Server.Port)
 		require.Equal(t, DebugLevel, cfg.Logging.Level)
 		require.Equal(t, true, cfg.Server.OpenAPI)
+		require.Equal(t, true, cfg.Server.OpenAPI)
 	})
 
 	t.Run("json_config", func(t *testing.T) {
@@ -89,6 +90,7 @@ logging:
 		require.Equal(t, 9090, cfg.Server.Port)
 		require.Equal(t, InfoLevel, cfg.Logging.Level)
 		require.Equal(t, false, cfg.Server.OpenAPI)
+		require.Equal(t, false, cfg.Server.OpenAPI)
 	})
 
 	t.Run("nonexistent_file", func(t *testing.T) {