shutdown proxy server when switching back to local; debounce vol slider

backend/player/dlna/dlnaplayer.go

@@ -197,6 +197,12 @@ func (d *DLNAPlayer) GetStatus() player.Status {
 	}
 }
 
+func (d *DLNAPlayer) Destroy() {
+	if d.proxyServer != nil {
+		go d.proxyServer.Shutdown(context.Background())
+	}
+}
+
 func getLocalIP() (string, error) {
 	interfaces, err := net.Interfaces()
 	if err != nil {

backend/player/jukebox/jukeboxplayer.go

@@ -140,6 +140,8 @@ func (j *JukeboxPlayer) GetStatus() player.Status {
 	}
 }
 
+func (j *JukeboxPlayer) Destroy() {}
+
 func (j *JukeboxPlayer) startAndUpdateTime() error {
 	beforeStart := time.Now()
 	if err := j.provider.JukeboxStart(); err != nil {

backend/player/player.go

@@ -27,6 +27,8 @@ type BasePlayer interface {
 
 	GetStatus() Status
 
+	Destroy()
+
 	// Event API
 	OnPaused(func())
 	OnStopped(func())