Replace MultichannelAudioSource with CaptureAudioSource, add
ProcessedAudioSource (audio_source_id + audio_processing_template_id),
remove MonoAudioSource and BandExtractAudioSource entirely.
Update store resolution to walk processed chains collecting template IDs.
Update all API schemas, routes, and frontend references.
Add all audio filters that transform AudioAnalysis data:
- Channel Extract, Band Extract (migration from old source types)
- Peak Hold, Gain, Noise Gate, Envelope Follower
- Spectral Smoothing, Compressor, Inverter, Beat Gate, Delay
All registered via AudioFilterRegistry with option schemas.
Add the foundation for audio processing filters, mirroring the existing
picture filter/postprocessing template system:
- AudioFilter base class, AudioFilterRegistry, AudioFilterOptionDef
- AudioProcessingTemplate dataclass + SQLite-backed store
- audio_filter_template meta-filter with recursive resolution
- Full REST API: CRUD templates + filter registry discovery
- Dependency injection wired in dependencies.py and main.py
alexei.dolgolyov