view: split the deferred FX-park drain by kind — restores stay forced, parks go one FX per idle tick behind a 1s coalescing delay

A rapid A→B→A flip now costs no plugin work: the restore cancels the still-pending
park outright. A park that has already written one FX carries a `partial` flag and is
superseded by its inverse rather than cancelled, so a half-parked chain is never stranded.

src/shell/actions/design_view_actions.cpp

@@ -26,7 +26,7 @@
 #include "shell/capture/track_guid.h"    // shared MediaTrack* -> canonical GUID key
 #include "shell/panel/panel_window.h"    // bankPanelInvalidate — footer toggle repaint
 #include "shell/view/view.h"             // applyMode + mintManagedLanes (D2 shell)
-#include "shell/view/view_fx_park.h"     // drainDeferredFxParks — see persistViewState
+#include "shell/view/view_fx_park.h"     // drainDeferredFxRestores — see persistViewState
 
 #define REAPERAPI_MINIMAL
 #define REAPERAPI_WANT_CountSelectedTracks
@@ -148,9 +148,11 @@ void persistViewState(PersistScope scope) {
     // BEFORE the model is serialized, and before the Save-As below can write a
     // .rpp: a deferred FX restore leaves the chain offline while the model has
     // already dropped the snapshot that would replan it. Why that combination is
-    // unrecoverable on reopen is at drainDeferredFxParks. Runs for BOTH scopes —
-    // the narrowed save still writes the key the half-applied park contradicts.
-    drainDeferredFxParks();
+    // unrecoverable on reopen is at drainDeferredFxRestores. Restores only — a
+    // pending PARK is safe to save over and converges on reopen. Runs for BOTH
+    // scopes: the narrowed save still writes the key the half-applied restore
+    // contradicts.
+    drainDeferredFxRestores();
 
     if (!g_session->view().membership().empty()) {
         ReaProject* proj = EnumProjects(-1, nullptr, 0);