Route startup preference load through adapter

src/app.cpp

@@ -29,7 +29,6 @@
 #include <Foundation/Foundation.h>
 #include "objc_utils.h"
 #endif
-#include "settings.h"
 
 App* App::I = nullptr; // singleton
 
@@ -223,7 +222,7 @@ void App::initLog()
     LOG("%s", g_version);
 
     LOG("load preferences");
-    if (!Settings::load())
+    if (!pp::panopainter::load_legacy_preferences())
         LOG("load preferences failed");
 }