Drain deferred FX parks before the view model is serialized; re-validate track handles per intent; pin the restore-plan round trip

src/shell/view/view.cpp

@@ -36,8 +36,7 @@
 #define REAPERAPI_WANT_TrackList_AdjustWindows
 #define REAPERAPI_WANT_UpdateArrange
 #define REAPERAPI_WANT_UpdateTimeline
-// Lane minting (D2 Wave 3): item-side lane reads/writes to assign each item to
-// its mode's managed lane.
+// Lane minting: item-side lane reads/writes assigning each item to its mode's lane.
 #define REAPERAPI_WANT_CountTrackMediaItems
 #define REAPERAPI_WANT_GetTrackMediaItem
 #define REAPERAPI_WANT_GetMediaItemInfo_Value
@@ -474,7 +473,8 @@ bool applyMode(ViewModeModel& model, const std::string& targetModeId, ReaProject
             // Enqueued FIRST: a park landing on this track's own pending restore
             // cancels it, and those ops are then the only surviving record of the
             // pre-park FX state. Snapshot ONCE — a snapshot already present means
-            // the track is still parked, so its live flags read as parked.
+            // the track is still parked, so recapturing would overwrite the true
+            // pre-park state with zeros and a later restore would hide it for good.
             const std::vector<FxOfflineOp> cancelled = deferFxPark(proj, guid);
             if (model.snapshot(guid) == nullptr)
                 model.storeSnapshot(guid, snapshotTrack(tr, cancelled));