feat: enhance local proxy error handling and configuration management

- Added signal for local proxy start failure to Settings.
- Updated CoreController to emit failure signals with descriptive messages when local proxy fails to start.
- Refactored XrayController to accept JSON configuration directly, improving configuration handling.
- Removed unused config file loading logic to streamline the XrayController's functionality.

client/ui/controllers/settingsController.cpp

@@ -56,6 +56,7 @@ SettingsController::SettingsController(const QSharedPointer<ServersModel> &serve
     toggleDevGatewayEnv(m_isDevModeEnabled);
 
     connect(m_settings.get(), &Settings::localProxySettingsChanged, this, &SettingsController::localProxySettingsUpdated);
+    connect(m_settings.get(), &Settings::localProxyStartFailed, this, &SettingsController::localProxyStartFailed);
 }
 
 QString getPlatformName()

client/ui/controllers/settingsController.h

@@ -153,6 +153,7 @@ signals:
     void isHomeAdLabelVisibleChanged(bool visible);
     void startMinimizedChanged();
     void localProxySettingsUpdated();
+    void localProxyStartFailed(const QString &message);
 
 private:
     QSharedPointer<ServersModel> m_serversModel;