Keep Discord Rich Presence connected

[lullabyX]

Problems

• Rich Presence could die permanently mid-session. Once the IPC path held a dead or non-socket entry, every later reconnect kept picking that same entry and failing, so presence stayed dark until SONE was restarted.
• Starting Discord after SONE did nothing. Reconnection only ever happened on a playback event, so a track already playing would never trigger one.
• Presence could linger after Discord quit, showing a track that was no longer playing.
• Users without Discord installed had their log filled with a connection warning on every attempt.