Bound the automation hold to the window the model has not caught up on, and make that authority model stated, enforced and tested

src/shell/instrument/reasampler_editor.h

@@ -420,7 +420,11 @@ private:
     std::vector<BankChoice> banks_;       // the named banks, for the filter tab strip
     std::vector<SampleChoice> visible_;   // samples_ narrowed by the active bank filter
     std::string selectedId_;              // the loaded capture ("" = empty state)
-    InstrumentParams params_;             // the ONE parameter set governing it
+    InstrumentParams params_;             // a CACHE of the processor's model (see below)
+    // The model generation params_ was taken at. That copy is authoritative only for the
+    // duration of a gesture; between gestures the sync tick re-seeds it whenever this differs
+    // from the processor's, because a commit writes the WHOLE set back.
+    std::uint32_t seenParamsGeneration_ = 0;
     ChannelMode channelMode_ = ChannelMode::Mono;  // mono/stereo toggle snapshot
 
     // Mirrors of the processor's persisted voice-system params, refreshed with the rest of the