Presence (orchestrated)
Parent shell's variant label cascades through m.Provider; Presence's descendant-walk exit makes the cascade work at unmount too.
Toggle to mount and unmount the list. The parent shell dictates the active label ("open" on enter, "closed" on exit) via m.Provider; passive children inherit that label and resolve their own variant map for it. Per-index staggers come from custom.
- fade#0
- slide#1
- scale#2
- rotate#3
- spring#4
- tween#5