fix: AI assistant not showing logs when run selected mid-session

[lmac-1]

Description

Users reported that logs weren't appearing in the AI assistant even when the "Send logs" checkbox was checked. Sentry showed context.log = null errors.

The bug occurred when:

1. User opens AI assistant for a job (no run selected)
2. User later selects a run from history
3. User checks "Send logs" and sends a message
4. Logs don't appear (context.log is null)

Root cause: follow_run_id was only stored during session creation. When users selected a run mid-session, the frontend sent follow_run_id in params, but the backend wasn't updating session.meta with the new run context, so logs couldn't be fetched.

Closes #4380

Solution

Store and propagate follow_run_id during message processing:

• Added maybe_put_follow_run_id_in_meta/2 helper in AiAssistantChannel to store follow_run_id from params in message.meta
• Updated MessageProcessor.update_session_with_job_context/2 to propagate follow_run_id from message.meta to in-memory session.meta
• This ensures maybe_add_run_logs can find the run_id and fetch logs during enrichment

Regression tests:

• Channel test: Verifies follow_run_id is stored in message.meta
• Message processor test: Verifies successful processing with follow_run_id
• Integration test: Verifies logs are fetched when follow_run_id is added mid-session

Validation steps

1. Open a workflow
2. Run it
3. But make sure no run is selected (viewed) in the canvas
4. Select a job node
5. Open the IDE
6. Now open the AI Assistant
7. Send a message to create a brand new AI session
8. Now select a run (click the History button in the IDE and pick a run, or just run the workflow again)
9. Now check the 'Send logs' checkbox in the AI Assistant (don't create a new AI session, continue with the session you created at step 7)
10. Now ask the AI Assistant if it 'sees' your logs. It should now see your logs. Ask questions about the logs or ask it to give more information to make sure it's not inventing the logs.

Additional notes for the reviewer

n/a

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[josephjclark]

This all seems very plausible @lmac-1 but I am still unable to reproduce this against main locally. I consistently see the logs being uploaded. I've tried following your steps several times - I must be doing something subtly wrong? I presume you've managed to repro?

I for one would be happy to merge it and see. We'd have to track it closely in prod.

[lmac-1]

Loom here to see it in action before and after the fix. The steps are a bit fiddly. https://www.loom.com/share/a569fbb2e34f4fb3bb006aea028ec50d

[josephjclark]

Ah fantastic @lmac-1 thank you - I'll take a look in the morning

[josephjclark]

That's amazing @lmac-1 I can repro!!!

[josephjclark]

Cannot comment on the technical solution but I've tested this and verified

What makes this hard is a litany of bugs around logging (from being able to tick Send Logs when none are available in the first place, to the assistant happily lying about the logs it receives). And the use-case reproduced feels a bit niche - is this the problem that's being reporting in production?

But @lmac-1 has 100% identified a bug and 100% fixed it as far as I'm concerned, so it's a Yes from me, Jim.

[midigofrank]

Nicely done

[midigofrank]

@lmac-1 looks like you have one failing test.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.42%. Comparing base (675fda7) to head (f9b7d5a).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4475   +/-   ##
=======================================
  Coverage   89.41%   89.42%           
=======================================
  Files         425      425           
  Lines       20245    20253    +8     
=======================================
+ Hits        18102    18111    +9     
+ Misses       2143     2142    -1     

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[lmac-1]

@midigofrank tests are now fixed. Thanks!