Update scan manager

Fix sound playback and play start sound immediately on button press

Reduce scan-start latency with lazy device detection

Unify scan.py with ScanManager and replace inline loggers

Fix file handle leaks in uploader upload methods

Fix thread safety, make ScanServer optional, add max_pages support

Fix stale device caching and optimize blank detection order

Extract shared format_size utility to piscan package

Add backup and debug script

Fixes

Fixes

Cleanup

Debugging

Enhance ZIP handling

Add simplex scan, fix sounds and bottom margin