planLaneMinting now takes the model + folder tree and splits a track visible in
2+ modes that carries own media (own-item span OR folder derived-visibility),
fixing an item dropped on a cross-mode folder leaking into every mode. Show-both
tracks are never force-split.
Pure planLaneMinting decides which tracks hold >1 mode's content and which managed
lane each item lands on; view.cpp applies it (I_FREEMODE/I_NUMFIXEDLANES/P_LANENAME/
I_FIXEDLANE) under one undo block, driven off the auto-tag detection tick. Manual lanes
and their items are never touched. Load-time reconcile rebuilds ownership from durable
lane names before reapplying active-mode visibility.
planToggle now enumerates all leaves in the FolderTree instead of only tagged
membership entries, so untagged (Arrange-member) tracks park in Design and
restore in Arrange. applyMode calls TrackList_AdjustWindows + UpdateArrange so
changes render immediately. Correct the stale "tagged-only" invariant comments.
applyMode now drives B_SHOWINTCP/B_SHOWINMIXER for every parent node
from visibleTracks(tree, targetMode); parents are never parked. Adds
restoreFxOffline by-index remap hazard note.
Reads I_FOLDERDEPTH into a FolderTree (pure view_tree helper, unit-tested),
snapshots to-be-parked tracks before parking, runs the D1 planner, and applies
park/restore flag + per-FX-offline writes under an undo block. Master and
mute/solo untouched; acts only on tagged tracks.
daniel