fix: handle uninitialized response in RespondingNettyPacket

- Modified `response` to use lazy initialization with `CompletableDeferred` for proper memory handling.
- Ensure exception completion if response is accessed after connection garbage collection.

Author: twisti-dev

surf-cloud-api/surf-cloud-api-common/src/main/kotlin/dev/slne/surf/cloud/api/common/netty/packet/RespondingNettyPacket.kt

@@ -38,7 +38,7 @@ abstract class RespondingNettyPacket<P : ResponseNettyPacket> : NettyPacket() {
      * A deferred response object for awaiting the associated response.
      */
     @InternalApi
-    val response = CompletableDeferred<P>()
+    val response by lazy { CompletableDeferred<P>() }
 
     /**
      * The connection through which the response will be sent.
@@ -120,6 +120,11 @@ abstract class RespondingNettyPacket<P : ResponseNettyPacket> : NettyPacket() {
         if (responseConnection == null) {
             log.atWarning()
                 .log("Cannot respond to packet ${this::class.simpleName} with session ID $uniqueSessionId: original connection has been garbage collected")
+
+            if ((::response.getDelegate() as Lazy<*>).isInitialized()) {
+                response.completeExceptionally(IllegalStateException("Original connection has been garbage collected"))
+            }
+
             return
         }