Feature Request: Support partial success for parallel steps (non-saga mode)

[sosiska]

Summary

Currently, floxy implements saga pattern where failure of one parallel step causes all siblings to stop/rollback and marks workflow as failed. Need option for batch processing mode where parallel steps run independently.

Current Behavior

wf := floxy.NewBuilder("batch-job", 1).
    Fork("process-items",
        func(b *floxy.Builder) { b.Step("item1", "handler") },
        func(b *floxy.Builder) { b.Step("item2", "handler") },
        func(b *floxy.Builder) { b.Step("item3", "handler") },
    ).
    Join("collect", floxy.JoinStrategyAll).
    Build()

If item2 fails:

• item1 and item3 are stopped (Fork) or rolled back (Parallel)
• Workflow status = failed
• Cannot retrieve results from item1 and item3

Expected Behavior

If item2 fails:

• item1 and item3 continue execution
• item1 status = completed, item3 status = completed, item2 status = failed
• Workflow status = partial (or partial_success, completed_with_errors)
• Can retrieve results from successful steps

Use Case

Batch processing: Running 5 parallel long-running tasks (e.g., installing Arch Linux on 5 machines, each takes ~1 hour). Each task is independent. If 2 installations fail, the 3 successful installations are still valuable and should be retrievable without full rollback.

What I've Tried

• DLQEnabled: Stops all active steps, requires manual intervention
• JoinStrategyAny: Join step doesn't fail, but workflow still triggers rollback
• Parallel instead of Fork: Siblings complete, but still performs rollback
• No OnFailure handlers: Steps complete but workflow still rolls back and marks as failed

None of these provide batch processing semantics where independent tasks can partially succeed.

Question

Is there a way to achieve this with current floxy features, or would this require a new mode/option? Happy to contribute a PR if this aligns with floxy's design goals.