[Patel Namraa (Namraa310806)]

Motivation & Context

Fixes a state isolation bug where pending State writes from a failed or cancelled workflow superstep can leak into a later successful Workflow.run() on the same Workflow instance.

State.set() stages writes in a pending buffer, which is committed only when a superstep completes successfully. However, when a superstep fails or is cancelled, the pending writes were not discarded.

Because workflow state persists across run() calls, a later successful superstep could call State.commit() and unintentionally commit stale writes from the previous failed run.

This results in silent state corruption: state written by a failed run can become part of the committed state of a later successful run.

Description & Review Guide

• What are the major changes?

  • Discard pending state when a superstep fails with an exception.
  • Discard pending state when a superstep is cancelled.
  • Ensure concurrent edge-runner execution cannot continue staging state after the failed superstep reaches the discard boundary.
  • Add regression tests covering failed supersteps and concurrent execution.

• What is the impact of these changes?

  • Pending writes from failed or cancelled supersteps are no longer able to leak into later successful runs.
  • Committed state from previous successful runs is preserved.
  • Successful supersteps continue to use the existing State.commit() behavior.
  • No public API or checkpoint serialization behavior is changed.

• What do you want reviewers to focus on?

  • Whether the failure/cancellation boundary correctly prevents pending state from a failed superstep from reaching a later commit.
  • Whether the concurrent edge-runner handling preserves the existing execution and error-propagation semantics.

Related Issue

Fixes #7859

Contribution Checklist

• The code builds clean without any errors or warnings
• All unit tests pass, and I have added new tests where possible
• The PR follows the Contribution Guidelines
• This PR is linked to an issue and there is no other open PR for this issue (see Related Issue above).
• This is not a breaking change. If it is a breaking change, add the breaking change label (or add "[BREAKING]" to the title prefix) — a workflow keeps the label and title prefix in sync automatically.

Extending #7880 and fixing CI failing workflows

[Patel Namraa (Namraa310806)]

Eduard van Valkenburg (@eavanvalkenburg) both issues addressed (cancellation handling + removed the mid-executor commit()), with regression tests for each. Let me know if anything else needs changing.