When users run any ocr command, the Node.js shim spawns a detached
background process that checks GitHub Releases for newer versions and
atomically replaces the binary. This ensures users stay on recent
versions without blocking their current command execution.
- Cooldown: checks at most once per hour (configurable via OCR_UPDATE_INTERVAL)
- Disable: set OCR_NO_UPDATE=1 to skip entirely
- Safety: PID lock prevents concurrent updates, SHA-256 checksum verification,
atomic rename ensures running processes are unaffected
