Frontend: Add a powered-off window/welcome screen

src/core/host_interface.cpp

@@ -49,7 +49,6 @@ bool HostInterface::InitializeSystem(const char* filename, const char* exp1_file
     m_system->SetExpansionROM(exp1_filename);
 
   // Resume execution.
-  m_running = true;
   return true;
 }
 

src/core/host_interface.h

@@ -33,5 +33,5 @@ protected:
   std::unique_ptr<AudioStream> m_audio_stream;
 
   std::unique_ptr<System> m_system;
-  bool m_running = false;
+  bool m_running = true;
 };