perf(cleanup): Optimize cleanup job

[Koc]

📝 Summary

This is continuation of the #8421.

Problem:

The text app cleanup background job took roughly 800 seconds per run. The loop over documents with no active session unconditionally called cleanupAttachments, even for documents that had unsaved changes and could not be reset. The same ~8,000 documents kept re-entering the cleanup loop every cron run, and cleanupAttachments is expensive because it resolves the file, reads Markdown content, scans the database, and iterates the attachment directory.

Solution:

• Attempt to resetDocument before running cleanupAttachments.
• Catch DocumentHasUnsavedChangesException:
  • If unsaved changes are recent (last step within 30 days), skip the document. Attachment references may only exist in the unsaved state, so cleaning them now would be incorrect.
  • If unsaved changes are older than 30 days, force-reset the document, log a warning, and then clean up attachments.
• Added a helper to fetch the latest step timestamp for a document.

Impact:

• Cleanup cron runtime dropped from ~800 seconds to ~20 seconds.
• Abandoned unsaved changes older than 30 days are now cleaned up instead of accumulating forever.

🏁 Checklist

• Code is properly formatted (npm run lint / npm run stylelint / composer run cs:check)
• Sign-off message is added to all commits
• Tests (unit, integration and/or end-to-end) passing and the changes are covered with tests
• Documentation (README or documentation) has been updated or is not required

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI tools
• The AI-generated content was reviewed, comprehended and tested by a human