Render figure PNGs before starting result uploads in log_async

[cachafla]

Pull Request Description

What and why?

TestSuiteRunner (used by run_documentation_tests) awaits TestResult.log_async() directly and so skipped the figure pre-serialization that TestResult.log() does. Each Plotly figure was therefore rendered with kaleido inside alog_figure while the log_test_results request was already in flight. Kaleido 1.x launches a fresh Chromium per figure and blocks the event loop while it runs, so with several figures the 30s VM_API_TIMEOUT expired on the results upload:

TimeoutError ... aiohttp/helpers.py TimerContext.__exit__
raise asyncio.TimeoutError from exc_val

Seen on the JupyterHub demo environment running application_scorecard_full_suite.ipynb on 2.13.12. In a fresh process on the same host the same POST completes in 20ms, which isolated in-flight rendering as the cause.

log_async() now pre-serializes all figure PNGs before creating any upload task, via a helper shared with log().

How to test

• uv run python -m unittest tests.test_results — includes the new test_test_result_log_async_pre_serializes_figures, which asserts the PNG cache is populated by the time alog_figure is called.
• On JupyterHub: %pip install --user "git+https://github.com/validmind/validmind-library@andres/fix-figure-upload-timeout", restart the kernel, rerun application_scorecard_full_suite.ipynb. Verified by @cachafla: the full suite logs without timeouts.

What needs special review?

_pre_serialize_figures() is now called twice on the log() path (once outside the loop, once inside log_async()); the second call is a no-op because the bytes are cached.

Dependencies, breaking changes, and deployment notes

None. The three failures in tests.test_api_client are pre-existing on main and unrelated.

Release notes

Fixed asyncio.TimeoutError when run_documentation_tests uploads results with several Plotly figures. Figures are now rendered before uploads start.

Checklist

• What and why
• Screenshots or videos (Frontend)
• How to test
• What needs special review
• Dependencies, breaking changes, and deployment notes
• Labels applied
• PR linked to Shortcut
• Unit tests added (Backend)
• Tested locally
• Documentation updated (if required)
• Environment variable additions/changes documented (if required)

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Pull requests must include at least one of the required labels: internal, highlight, enhancement, bug, deprecation, documentation. Except for internal, pull requests must also include a description in the release notes section.

[github-actions]

Pull requests must include at least one of the required labels: internal, highlight, enhancement, bug, deprecation, documentation. Except for internal, pull requests must also include a description in the release notes section.