xtc/docs/COMPOSITION_WORKFLOWS.md

Arrangement and composition workflows

All mutations run on the control thread through the existing stop, history and prepared-plan workflow. No new dependencies are required.

Phase 58 — Persistent Arrangement Markers

Edit/Markers/Set at cursor adds or renames a marker; Remove at cursor removes the exact tick key. Markers draw names and vertical guides in the arrangement and survive project save/load and undo. Up to 128 markers are supported. Names may overlap visually when markers are close; markers do not change playback by themselves.