another fix fix(sdk): pick up a user message that arrives during an async step

Approved the PR. Same thing I feel here too: this code and behavior is becoming too complex to vouch for, and/or to verify correctness, and/or to know the behavior of the software; we could try to keep tabs on it by documenting behavior. Software engineering has always wanted to do that; UML and sequence diagrams and flow charts and all come from attempting to tame complexity. If before agents got good that was still too much work after all, now it’s not; just needs us to play, at least occasionally, with it, until we find a way we like. Once it exists, it also acts as a soft guardrail for the next agent running on that code.

I think we need a big refactory

nod I do remember that this behavior, stuff that happens during step and gets lost, has been somewhat of an afterthought. Now we know what we want here

@fresh-machine-37269 Can you understand how we are doing streaming in the sdk + agent-canvas and create a small schema to explain how it works. Moreover, can you propose different architectures to make it better? You can also looking in other open source repository to have inspiration how people is managing this problem.