Split FX out of the park plan: flag-only plans, derived online-first FX work list, two-half record release, applied-state fingerprint

src/shell/view/view.cpp

@@ -17,6 +17,7 @@
 
 #include "shell/capture/item_read.h"
 #include "core/view/fx_offline.h"
+#include "core/view/fx_state.h"
 #include "core/view/lane_keys.h"
 #include "core/view/solo_cache.h"
 #include "shell/capture/track_guid.h"
@@ -471,7 +472,8 @@ bool applyMode(ViewModeModel& model, const std::string& targetModeId, ReaProject
             MediaTrack* tr = resolve(trackByGuid, guid);
             if (!tr || !trackStillLive(project, tr)) continue;  // stale/deleted GUID — prune
 
-            const TrackApplyResult r = restoreTrack(model, guid, tr, tp.fxOffline, tp.flags);
+            const std::vector<FxOfflineOp> fxOps = view::fxRestoreTargets(model, guid);
+            const TrackApplyResult r = restoreTrack(model, guid, tr, fxOps, tp.flags);
             if (r.wrote) wrote = true;
             if (r.fxMoved) undoMask |= UNDO_STATE_FX;
             if (r.drops.total() > 0) { fxDrops.add(r.drops); ++fxDropTracks; }

src/shell/view/view_fx_park.cpp

@@ -203,15 +203,17 @@ TrackApplyResult restoreTrack(ViewModeModel& model, const std::string& guid, Med
     for (const FxOfflineWrite& w : res.writes)
         if (setOfflineIfChanged(tr, w.fxIndex, w.offline)) out.fxMoved = out.wrote = true;
     out.drops = res.drops;
+    // The chain is back online HERE, which is the only thing that spends the FX half.
+    model.releaseSnapshotFx(guid);
 
     if (applyFlags(tr, flags, out.fxMoved)) out.wrote = true;
+    model.releaseSnapshotFlags(guid);
 
-    // Unconditional, even when every write above was elided: the snapshot is consumed
+    // Unconditional, even when every write above was elided: the record is consumed
     // here, so this apply changed state and is not repeatable — and `wrote`, whose one
     // reader asks exactly that, would be a lie at false. NOT a claim about what the
-    // undo record holds: the block never carries the snapshot either way, that being
+    // undo record holds: the block never carries the record either way, that being
     // model state persisted after Undo_EndBlock2 (src/shell/view/CLAUDE.md).
-    model.clearSnapshot(guid);
     out.wrote = true;
     return out;
 }