Release post-process slot immediately after main extraction completes.
All slow post-extraction work (nested extraction, auto-rename, archive
cleanup, link/sample removal, empty directory cleanup, MKV collection)
now runs in background via runDeferredPostExtraction so the next package
can start unpacking without delay.
- Export hasAnyFilesRecursive, removeEmptyDirectoryTree, cleanupArchives
from extractor.ts for use in deferred handler
- Import removeDownloadLinkArtifacts, removeSampleArtifacts from cleanup
- Expand runDeferredPostExtraction with full post-cleanup pipeline:
nested extraction, rename, archive cleanup, link/sample removal,
empty dir tree removal, resume state clearing, MKV collection
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
