Trajectory replay: Fix a few corner cases

[li-boxuan]

End-user friendly description of the problem this fixes or functionality that this introduces

• Include this change in the Release Notes. If checked, you must provide an end-user friendly description for your change below

Fix two corner cases handling in trajectory replay feature.

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Give a summary of what the PR does, explaining any non-trivial design decisions

Two corner cases were missing in the previous PR #6215:

1. When there's a wait_for_response message, replay gets stuck, waiting for user's response, which doesn't make sense when in the middle of a replay. This is demonstrated in demo2.json and demo3.json.
2. The trajectory dumped from the GUI would contain environmental actions, which shall be skipped during replay. This is demonstrated in demo1.json (Note: trajectory export from GUI is not available yet; demo1.json is downloaded using the PR (feat) Add button to export trajectory on chat panel #6378).

demo1.json - GUI mode: downloaded from web GUI
demo2.json - Headless mode: after demo1 replay, add a user message, and finish
demo3.json - Headless mode: a replay of demo2. Note: demo2.json and demo3.json only differ in step id, timestamp, hostname, and wait_for_response attribute.

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Link of any specific issues this addresses

Part of #6049

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To run this PR locally, use the following command:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:aff6136-nikolaik   --name openhands-app-aff6136   docker.all-hands.dev/all-hands-ai/openhands:aff6136

[enyst]

Looking at demo2, this seems strange:

{"id": 13, "timestamp": "2025-01-20T22:23:36.002374", "source": "agent", "action": "message", "args": {"content": null, "image_urls": null, "wait_for_response": true}, "timeout": 120}

A MessageAction with null content, null image, and wait_for_response = true ?

Aaahh I think I see how that happened, you literally said it, you added something. The previous is a MessageAction with content where the agent is asking the user a question, but its wait_for_response = false... because this PR is setting it false, right?

[li-boxuan]

Looking at demo2, this seems strange:

{"id": 13, "timestamp": "2025-01-20T22:23:36.002374", "source": "agent", "action": "message", "args": {"content": null, "image_urls": null, "wait_for_response": true}, "timeout": 120}

A MessageAction with null content, null image, and wait_for_response = true ?

Aaahh I think I see how that happened, you literally said it, you added something. The previous is a MessageAction with content where the agent is asking the user a question, but its wait_for_response = false... because this PR is setting it false, right?

That's correct!

[li-boxuan]

Aside, I do realize this would become a bug farm... and I'll make sure to add some E2E tests before checking in the user-facing replay functionality in #6348

[enyst]

(not a 'review' comment, and this is cool anyway)
Just the other day, I was playing with Gemini-2.0-thinking, and it's been a lot of fun for coding-adjacent tasks! Among others, it explored a lot of openhands repo, tracked down every occurrence of oh_action and followed the execution flow up in frontend, downstream in backend, until it figured out everything about them. It makes itself mini-plans on the fly and does follow up, very cool!

Anyway, so in the server, all those are set with source USER, but they're quite different, e.g. agent change actions, prompt confirmations, CmdRunActions (ran by user in terminal), MessageActions. I think none should be a problem, and cmd run actions are good for replay! We do want to replay those, if we want to achieve a similar state (hopefully), and of course, they'd be in context.

[li-boxuan]

Yeah I think I did this check as a hack at the beginning - probably just to work around the wait_for_confirmation thing. It's been more and more clear that source USER events should be replayed too.

[enyst]

Thank you, this feature is a thing of beauty!