Make bars navigable and editable with _meta export
Navigation:
- SubObjects: bar → voice (with chevron when offsets exist) → offsets
- PaneCP shortView handles voice and offset types
FO pane:
- Bar: editable beats_per_minute, stress_pattern (serialized as
groups string), upper/lower stress bounds and tempo shape via
ShapeEditor; sets bar.isDirty on change
- Voice: read-only name, articles, motifs, offset count
- Offset: read-only tick, stem notes and clusters as label strings
(note re-serialization deferred)
Export:
- exporter.patchScore() now accepts optional bars[] parameter
- Splits rawScoreText by \n---\n; instruments patched in header,
dirty bar _meta blocks regenerated, voice note lines kept verbatim
- ast-parser buildBar() adds isDirty:false
- PaneCP passes scoreModel.bars to patchScore
9eb4add695