feat(defers): add transformDeferInput middleware hook

[Linell]

Summary

Add transformDeferInput and support for async defer validations

Checklist

• Added a docs PR that references this PR
• Added unit/integration tests
• Added changesets if applicable

Related

Old, PR: #1559
Revert: #1563
Follow Up: #1560

[linear-code]

EXE-1815

[changeset-bot]

🦋 Changeset detected

Latest commit: 422d6f8

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
inngest	Patch

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[mendral-app]

LGTM

All prior comments remain addressed. New changes since last review (abort handle, DeferAbort dedup moved to drain(), async validator support) are clean. The riskiest hunk — prepareDeferOp catching rejections and resolving null to drop ops, with drain() filtering nulls — handles the error path correctly and prevents unhandled rejections from propagating. No new issues found.

What this PR does

Adds transformDeferInput middleware hook and async schema validator support for deferred functions. Refactors LazyOps to store promises (async prep settles after sync ID reservation), moves experiment-key injection after validation/middleware, adds DeferAbort dedup at drain time, and returns an abort() handle from defer(). Integration tests cover all new paths.

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