- Add AlsaDirectError enum for structured error classification
- Add BitPerfectMode enum to track runtime bit-perfect status
- Implement automatic fallback: hw fails with format error → try plughw
- Abort on non-recoverable errors (busy, permissions, invalid params)
- Respect ALSA plugin selection from UI settings
- Log runtime mode for debugging
This allows SMSL-class DACs that fail on hw: to work via plughw:
while maintaining bit-perfect guarantees (format conversion only,
no resampling).
cc
vicrodh
da5ec2abcb