[Bug]:block()/blockFirst()/blockLast() are blocking, which is not supported in thread reactor-http-nio-3

[cs0512]

源码提供的代码示例中
AutoContextMemory.summaryPreviousRoundConversation方法中
Msg block =
model.stream(newMessages, null, options)
.concatMap(chunk -> processChunk(chunk, context))
.then(Mono.defer(() -> Mono.just(context.buildFinalMessage())))
.block();
这块代码有问题，需要修复下

[Alexxigang]

I reproduced this locally in the AutoContextMemory hook path: when compressIfNeeded() runs on a Reactor non-blocking thread, the internal summarization flow hits �lock() and fails before PreReasoningEvent can finish. I have a fix in progress that moves the compression work onto a bounded-elastic scheduler and adds regression tests for both the hook path and direct async compression.

[Alexxigang]

Opened PR: #1235

This moves AutoContextMemory compression off Reactor non-blocking threads before pre-reasoning continues, and adds regression tests for both the hook path and direct async compression.