Manual Sync Offset Setting
- Added Manual Sync Offset control in Settings (±5 seconds range)
- Positive values delay playback, negative values advance it
- Offset is applied when connecting to a server
- Works alongside GroupSync calibration tool offsets
Stats Display Cleanup
- Removed misleading "Sync Error" metric (was showing processing lead time)
- The remaining "Sync Error" now shows accurate DAC-based sync measurement
- This value represents actual playback position vs expected position