Add the FX reclaimer: a debounced, time-boxed convergence loop that offlines parked chains and restores returning ones off the switch path

src/app/main.cpp

@@ -38,6 +38,7 @@
 #include "shell/panel/panel_input.h"             // bankPanelRefresh / bankPanelNotifyProjectLoaded
 #include "shell/panel/panel_window.h"            // panel lifecycle (init/toggle/open-query/shutdown)
 #include "shell/persist/session.h"               // ReaSamplerSession
+#include "shell/view/fx_reclaim.h"               // the FX reclaimer's tick
 #include "shell/view/view.h"                     // applyMode
 #include "shell/view/view_lanes.h"               // reconcileManagedLanes
 #include "shell/view/view_reconcile.h"           // reconcileAppliedFlags
@@ -215,6 +216,15 @@ static void OnTimer()
         reasampler::applyMode(g_session.view(), g_session.view().activeModeId(), nullptr);
     }
 
+    // Converge the FX chains toward what the view state says they should be — the
+    // 1897ms of TrackFX_SetOffline a mode switch no longer pays synchronously. Same
+    // idle discipline as the realtime fast path above: a SINGLE BOOL TEST when there is
+    // nothing to converge. Ordered AFTER the load block deliberately — a reload replaces
+    // the view model wholesale, and the applyMode above is what re-derives the queue
+    // from it, so draining first would spend a tick against the outgoing model.
+    if (reasampler::g_fxReclaimPending)
+        reasampler::fxReclaimTick(g_session.view(), nullptr);
+
     reasampler::bankPanelRefresh();  // cheap fingerprint compare; no-op when unchanged/closed
 }