Gate the FX reclaimer on the transport, both directions; move the release's persist off the drain and onto the project save

The drain no longer dirties a project on its own initiative — a spent park record rides the user's next save via OnSaveExtensionConfig.

src/shell/persist/session.h

@@ -144,6 +144,13 @@ public:
     // Returns on the SAME rule as saveToActiveProject above, prohibition included.
     bool saveViewStateOnly();
 
+    // The same write with the dirty mark OMITTED, for a caller already inside REAPER's
+    // own project save: marking dirty there would leave the project modified the instant
+    // it was saved, which is the whole reason that caller exists (fx_reclaim's
+    // ReleaseFlush). Not a general-purpose sibling — a mutation site that skips the dirty
+    // mark silently loses its write when the user closes without saving.
+    bool flushViewState();
+
     // Report-only prune dry-run: feeds the pure core with (present, referenced,
     // owned) — `present` from the folder enumeration, the other two from the
     // tracking authority. FAIL-SAFE: tracking state the authority cannot read