[Bug]: A2A HTTP protocol upgrade fails when using Otel auto instrumentation due Netty

### What happened?

Related to this issue: https://github.com/a2aproject/a2a-java/issues/502

When adding OTEL auto instrumentation to my application, by using the Java OTEL agent, the A2A client fails to negotiate an upgrade to HTTP 2. Look below for the logs in the application:

The reason behind the issue:
```
The OTel Java agent's Netty bytecode instrumentation breaks Vert.x's HTTP/2 cleartext (h2c) upgrade handling. When Java's HttpClient (used by the A2A SDK) sends Upgrade: h2c, the instrumented server drops the connection instead of responding with 101 Switching Protocols.
```

To fix the issue:

```
Added OTEL_INSTRUMENTATION_NETTY_ENABLED=false to the cooking-agent and delivery-agent K8s manifests. This disables only the
Netty-level instrumentation while keeping higher-level Quarkus/Vert.x observability intact.
```

If you add the following `JAVA_OPTS` to your application, you can see the requests being created by the A2A library and how it fails to upgrade the connection only when OTEL instrumentation is on.

```
- name: JAVA_OPTS
value: -Djdk.httpclient.HttpClient.log="errors,requests,headers,frames:control:data:window,ssl,trace,channel"
```

### Relevant log output

```shell
Application Error:

[io.quarkus.vertx.http.runtime.QuarkusErrorHandler] (executor-thread-2) HTTP Request to /mgmt/processOrder failed, error id: 1cdeb479-c8fe-41f0-9802-3fe3e05490ec-3:
jakarta.enterprise.inject.CreationException: Error creating synthetic bean [aLyk-Wj_mwEcG8EdDSX8kol41oQ]: java.lang.RuntimeException: io.a2a.spec.A2AClientError: Failed to obtain agent
card
at com.pizzavibe.store.workflows.PizzaOrderWorkflow_aLyk-Wj_mwEcG8EdDSX8kol41oQ_Synthetic_Bean.create(Unknown Source)
at com.pizzavibe.store.workflows.PizzaOrderWorkflow_aLyk-Wj_mwEcG8EdDSX8kol41oQ_Synthetic_Bean.create(Unknown Source)
at io.quarkus.arc.impl.AbstractSharedContext.createInstanceHandle(AbstractSharedContext.java:119)
at io.quarkus.arc.impl.AbstractSharedContext$1.get(AbstractSharedContext.java:38)
at io.quarkus.arc.impl.AbstractSharedContext$1.get(AbstractSharedContext.java:35)
at io.quarkus.arc.generator.Default_jakarta_enterprise_context_ApplicationScoped_ContextInstances.ch24(Unknown Source)
at io.quarkus.arc.generator.Default_jakarta_enterprise_context_ApplicationScoped_ContextInstances.computeIfAbsent(Unknown Source)
at io.quarkus.arc.impl.AbstractSharedContext.get(AbstractSharedContext.java:35)
at io.quarkus.arc.impl.ClientProxies.getApplicationScopedDelegate(ClientProxies.java:23)
at com.pizzavibe.store.workflows.PizzaOrderWorkflow_aLyk-Wj_mwEcG8EdDSX8kol41oQ_Synthetic_ClientProxy.arc$delegate(Unknown Source)
at com.pizzavibe.store.workflows.PizzaOrderWorkflow_aLyk-Wj_mwEcG8EdDSX8kol41oQ_Synthetic_ClientProxy.processPizzaOrder(Unknown Source)
at com.pizzavibe.store.StoreMgmtResource.processOrder(StoreMgmtResource.java:48)
at com.pizzavibe.store.StoreMgmtResource$quarkusrestinvoker$processOrder_0f393797cf8d9883eee70376b7ab7d4e45e97c49.invoke(Unknown Source)
at org.jboss.resteasy.reactive.server.handlers.InvocationHandler.handle(InvocationHandler.java:29)
at io.quarkus.resteasy.reactive.server.runtime.QuarkusResteasyReactiveRequestContext.invokeHandler(QuarkusResteasyReactiveRequestContext.java:190)
at org.jboss.resteasy.reactive.common.core.AbstractResteasyReactiveContext.run(AbstractResteasyReactiveContext.java:147)
at io.quarkus.vertx.core.runtime.VertxCoreRecorder$15.runWith(VertxCoreRecorder.java:666)
at org.jboss.threads.EnhancedQueueExecutor$Task.doRunWith(EnhancedQueueExecutor.java:2651)
at org.jboss.threads.EnhancedQueueExecutor$Task.run(EnhancedQueueExecutor.java:2630)
at org.jboss.threads.EnhancedQueueExecutor.runThreadBody(EnhancedQueueExecutor.java:1622)
at org.jboss.threads.EnhancedQueueExecutor$ThreadBody.run(EnhancedQueueExecutor.java:1589)
at org.jboss.threads.DelegatingRunnable.run(DelegatingRunnable.java:11)
at org.jboss.threads.ThreadLocalResettingRunnable.run(ThreadLocalResettingRunnable.java:11)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: java.lang.RuntimeException: io.a2a.spec.A2AClientError: Failed to obtain agent card
at dev.langchain4j.agentic.a2a.DefaultA2AClientBuilder.agentCard(DefaultA2AClientBuilder.java:83)
at dev.langchain4j.agentic.a2a.DefaultA2AClientBuilder.(DefaultA2AClientBuilder.java:63)
at dev.langchain4j.agentic.a2a.DefaultA2AService.a2aBuilder(DefaultA2AService.java:24)
at dev.langchain4j.agentic.AgenticServices.a2aBuilder(AgenticServices.java:271)
at dev.langchain4j.agentic.AgenticServices.createA2AClientAgent(AgenticServices.java:786)
at dev.langchain4j.agentic.AgenticServices.createBuiltInAgentExecutor(AgenticServices.java:764)
at dev.langchain4j.agentic.AgenticServices.createSubagent(AgenticServices.java:700)
at dev.langchain4j.agentic.AgenticServices.lambda$createSubagents$0(AgenticServices.java:694)
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197)
at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:1024)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:575)
at java.base/java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260)
at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:616)
at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:622)
at java.base/java.util.stream.ReferencePipeline.toList(ReferencePipeline.java:627)
at dev.langchain4j.agentic.AgenticServices.createSubagents(AgenticServices.java:695)
at dev.langchain4j.agentic.AgenticServices.buildSequentialAgent(AgenticServices.java:394)
at dev.langchain4j.agentic.AgenticServices.createComposedAgent(AgenticServices.java:355)
at dev.langchain4j.agentic.AgenticServices.createAgenticSystem(AgenticServices.java:324)
at io.quarkiverse.langchain4j.agentic.runtime.AgenticRecorder$1.apply(AgenticRecorder.java:52)
at io.quarkiverse.langchain4j.agentic.runtime.AgenticRecorder$1.apply(AgenticRecorder.java:36)
at com.pizzavibe.store.workflows.PizzaOrderWorkflow_aLyk-Wj_mwEcG8EdDSX8kol41oQ_Synthetic_Bean.createSynthetic(Unknown Source)
... 25 more
Caused by: io.a2a.spec.A2AClientError: Failed to obtain agent card
at io.a2a.client.http.A2ACardResolver.getAgentCard(A2ACardResolver.java:105)
at io.a2a.A2A.getAgentCard(A2A.java:187)
at io.a2a.A2A.getAgentCard(A2A.java:155)
at io.a2a.A2A.getAgentCard(A2A.java:142)
at dev.langchain4j.agentic.a2a.DefaultA2AClientBuilder.agentCard(DefaultA2AClientBuilder.java:81)
... 48 more
Caused by: java.io.IOException: HTTP/1.1 header parser received no bytes
at java.net.http/jdk.internal.net.http.HttpClientImpl.send(HttpClientImpl.java:970)
at java.net.http/jdk.internal.net.http.HttpClientFacade.send(HttpClientFacade.java:133)
at io.a2a.client.http.JdkA2AHttpClient$JdkGetBuilder.get(JdkA2AHttpClient.java:212)
at io.a2a.client.http.A2ACardResolver.getAgentCard(A2ACardResolver.java:99)
... 52 more
Caused by: java.io.IOException: HTTP/1.1 header parser received no bytes
at java.net.http/jdk.internal.net.http.common.Utils.wrapWithExtraDetail(Utils.java:412)
at java.net.http/jdk.internal.net.http.Http1Response$HeadersReader.onReadError(Http1Response.java:590)
at java.net.http/jdk.internal.net.http.Http1AsyncReceiver.checkForErrors(Http1AsyncReceiver.java:302)
at java.net.http/jdk.internal.net.http.Http1AsyncReceiver.flush(Http1AsyncReceiver.java:268)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$LockingRestartableTask.run(SequentialScheduler.java:182)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$CompleteRestartableTask.run(SequentialScheduler.java:149)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(SequentialScheduler.java:207)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
... 1 more
Caused by: java.io.EOFException: EOF reached while reading
at java.net.http/jdk.internal.net.http.Http1AsyncReceiver$Http1TubeSubscriber.onComplete(Http1AsyncReceiver.java:601)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$ReadSubscription.signalCompletion(SocketTube.java:648)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$InternalReadSubscription.read(SocketTube.java:853)
at java.net.http/jdk.internal.net.http.SocketTube$SocketFlowTask.run(SocketTube.java:181)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(SequentialScheduler.java:207)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler.runOrSchedule(SequentialScheduler.java:280)
at java.net.http/jdk.internal.net.http.common.SequentialScheduler.runOrSchedule(SequentialScheduler.java:233)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$InternalReadSubscription.signalReadable(SocketTube.java:782)
at java.net.http/jdk.internal.net.http.SocketTube$InternalReadPublisher$ReadEvent.signalEvent(SocketTube.java:965)
at java.net.http/jdk.internal.net.http.SocketTube$SocketFlowEvent.handle(SocketTube.java:253)
at java.net.http/jdk.internal.net.http.HttpClientImpl$SelectorManager.handleEvent(HttpClientImpl.java:1477)
at java.net.http/jdk.internal.net.http.HttpClientImpl$SelectorManager.lambda$run$3(HttpClientImpl.java:1422)
at java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
at java.net.http/jdk.internal.net.http.HttpClientImpl$SelectorManager.run(HttpClientImpl.java:1422)
```

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