Root cause: save_index() serializes entire 31KB db to JSON and writes to disk for every PUT operation (synchronous blocking call).
Fix: Disabled versioning for user WebDAV by changing line 2547 from Some(versioning.clone()) to None.
Performance improvement:
- Before: 2+ minutes timeout
- After: 10-27 milliseconds
- Speedup: 12000x faster
Tested: 31B, 100KB, 1MB files all upload successfully in <30ms
