Migrate resume_flow_run from sync_compatible to async_dispatch

[devin-ai-integration]

This PR migrates resume_flow_run from the @sync_compatible decorator to the @async_dispatch pattern, following the approach established in #19632.

Changes:

• Create aresume_flow_run as the explicit async implementation
• Convert resume_flow_run to a sync function decorated with @async_dispatch(aresume_flow_run)
• Export aresume_flow_run from main.py and __init__.py
• Add tests for both sync and async code paths
• Add None checks for flow_run.state and response.state for robustness (previously would raise AttributeError if state was None)

Review notes:

• The None checks on lines 474 and 480 (async) and 498 and 504 (sync) are new defensive additions - the original code assumed state was always present
• Tests verify the async dispatch behavior but don't test the full success path for resuming a paused flow (requires deployment setup)

Closes #15008 (partial - this is one function in the incremental migration)

Link to Devin run: https://app.devin.ai/sessions/b9cefdf38a744dfd8403c97230ef5cd1
Requested by: Nate Nowack ([email protected]) / @zzstoatzz

Checklist

• This pull request references any related issue by including "closes <link to issue>"
• If this pull request adds new functionality, it includes unit tests that cover the changes
• If this pull request removes docs files, it includes redirect settings in mint.json.
• If this pull request adds functions or classes, it includes helpful docstrings.

[devin-ai-integration]

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[codspeed-hq]

CodSpeed Performance Report

Merging #19792 will not alter performance

_{Comparing devin/1765821659-migrate-resume-flow-run-async-dispatch (ffa9331) with main (97d3356)}

Summary

✅ 2 untouched