more cleanup

internal/functions/registry.go

@@ -67,7 +67,14 @@ func GetFunctionDeclarations() string {
 }
 
 func GetRegisteredFunctions() map[string]Function {
-	return functionRegistry
+	registryMutex.RLock()
+	defer registryMutex.RUnlock()
+
+	result := make(map[string]Function, len(functionRegistry))
+	for k, v := range functionRegistry {
+		result[k] = v
+	}
+	return result
 }
 
 func RegisterFunction[T Args, R any](name string, fn GoFunc[T, R]) {