- Fix persisted uploads stuck in 'processing': updatePendingUpload now
updates both in-flight and persisted state arrays
- Fix duplicate filename collision: key pending upload IDs by batch index
instead of filename, thread index through onUploadComplete callback
- Fix modal premature close on multi-file upload: track expected/completed
counts and only fire onUploadSuccess after all files resolve
Co-authored-by: Cursor <cursoragent@cursor.com>
