fix(outbox): prevent bulk cleanup from starving delivery

[icecrasher321]

Summary

• Retire connector-upload cleanup guards in the attachment transaction; rollback still leaves orphan cleanup available, and replaced bytes retain their separate cleanup event.
• Serve outbox event types in rounds using an indexed queue head, so bulk maintenance cannot consume every delivery slot. Keep claims sequential, cap delivery and stale-lease recovery, and skip handlers that cannot fit the remaining runtime.
• Add a concurrent partial index and PostgreSQL CI regressions covering a large backlog, overlapping workers, deadlines, and upload recovery.

Type of Change

• Bug fix

Testing

230 targeted unit tests and 30 PostgreSQL CI tests pass. PostgreSQL tests cover 100,000 pending plus 100,000 completed events, index selection, concurrent claims, bounded reaping, attachment rollback, and replaced-object cleanup. Workspace lint/type-check, all audits, and migration safety checks pass.

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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1 Skipped Deployment

Project	Deployment	Actions	Updated
docs	Skipped		Sep 9, 2026 5:38pm UTC

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; no new actionable issue or outstanding previous finding remains.

Summary

• Raises the outbox processing batch limit and adds fair, sequential, concurrency-safe per-type claims.
• Adds a concurrent partial PostgreSQL index supporting ready-event-type scheduling.
• Bounds stale processing-row recovery and adds PostgreSQL coverage for large backlogs, overlapping workers, deadlines, and connector-upload recovery.
• Updates CI to run the new PostgreSQL integration suites.

Diagram

%%{init: {'theme': 'neutral'}}%%
flowchart TD
  A[Discover ready event types] --> B[Select next eligible type]
  B --> C{Handler fits remaining runtime?}
  C -- No --> D[Remove type from this invocation]
  C -- Yes --> E[Claim earliest event for type]
  E --> F[Run handler]
  F --> G[Persist completion, retry, or dead letter]
  G --> H{Batch capacity remains?}
  H -- Yes --> B
  H -- No --> I[Return bounded results]
  D --> H

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[icecrasher321]

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[icecrasher321]

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[icecrasher321]

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