Extension stamps a monotonic bank_generation counter, bumped at content
mutations; the VST3 instrument polls it off-thread on an editor timer and
consumes assignment requests, refreshing playback hands-free.
Extend BANK_PRUNE_FOLDER from report-only to dry-run→confirm-with-manifest→
delete exactly the pure-core orphan set (fresh recompute, stale entries skipped).
Windows routes to Recycle Bin (SHFileOperation+FOF_ALLOWUNDO), else unlink.
New pure prune_button module + footer button dispatching the action id. No
ext-state write, no undo point (deletion is not REAPER-undoable).
Register toggle/activate/tag/untag/show-both actions driving the D2
shell and D3 model; reapply saved active mode on project load via a
persist load-signal seam. Shared guidString helper; pure nextModeId
unit-tested.
daniel