Include metadata like session_id in logs

[raymyers]

• This change is worth documenting at https://docs.all-hands.dev/
• Include this change in the Release Notes. If checked, you must provide an end-user friendly description for your change below

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

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

The goal is to improve observability and be able to answer questions like "what happened in this session" or "how many sessions are experiences errors".

This PR includes add metadata in logging when available, such as session_id and user_id. These will show up as fields in json logging mode, added in #7034.

Naming of Session ID: These logs using the field session_id, but other places in the codebase call it conversation_id or sid, I'm open to whichever we want to standardize on.

Deprecating MonitoringListener: This replaces use of MonitoringListener (added recently in #6929) with logs that populate the signal extra field with these values.

• signal: agent_session_start
• signal: create_conversation
• signal: agent_status_error

If this is successful, a future change can likely remove the MonitoringListener abstraction completely.

LoggerAdapter: In Session and AgentSession, the LoggerAdapter pattern was used to add metadata at the class level instead of each log statement. See Logging Cookbook in the official Python docs. We want to include both common fields (like session_id) and additional fields in the extra arg of a single log statement, so LoggerAdapter is subclassed to do the same as Python 3.13's merge_extra option will provide.

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Link of any specific issues this addresses.

[raymyers]

Related: Discussed with @mamoodi that the LOG_JSON mode is probably with documenting so I'm going to make a separate PR adding a logging.md to developer docs.

[raymyers]

Related: Discussed with @mamoodi that the LOG_JSON mode is probably with documenting so I'm going to make a separate PR adding a logging.md to developer docs.

Created #7147, could assign to me if you like.

[raymyers]

This library does a similar thing to the adapter and extra fields formatter in this PR, but I'm not quite convinced that it's worth pulling in a library for.

https://terseus.github.io/python-logging-with-context/

[enyst]

LGTM!

[enyst]

If you're happy with it, we can take this in?

[raymyers]

If you're happy with it, we can take this in?

@enyst Yep, I think this one is good to go thanks!