fix: implement manual pong responses and remove internal ping interval to improve WebSocket connection stability

Author: sameerasw

app/src/main/java/com/sameerasw/airsync/utils/WebSocketMessageHandler.kt

@@ -425,6 +425,10 @@ object WebSocketMessageHandler {
 
     private fun handlePing(context: Context) {
         try {
+            // Reply immediately with lightweight pong message to keep session active
+            val pongJson = "{\"type\":\"pong\",\"data\":{}}"
+            WebSocketUtil.sendMessage(pongJson)
+
             // Respond to ping with current device status to keep connection alive
             // We must force sync here because the server expects a response to every ping
             SyncManager.checkAndSyncDeviceStatus(context, forceSync = true)

app/src/main/java/com/sameerasw/airsync/utils/WebSocketUtil.kt

@@ -76,10 +76,6 @@ object WebSocketUtil {
             .connectTimeout(15, TimeUnit.SECONDS)
             .writeTimeout(10, TimeUnit.SECONDS)
             .readTimeout(0, TimeUnit.SECONDS) // Keep connection alive
-            .pingInterval(
-                20,
-                TimeUnit.SECONDS
-            ) // Send ping every 20 seconds
             .build()
     }