Decouple the instrument reload from VST3 activation, and make the master meter's accumulate exact

src/shell/instrument/reasampler_editor.h

@@ -457,7 +457,8 @@ private:
     bool searchFocused_ = false;          // whether the search box has keyboard focus
 
     // The MASTER deck's meter, advanced from the published block magnitudes on the sync tick
-    // (see onSyncTimer for why it runs mid-drag too). meterTickMs_ 0 = never advanced.
+    // (see onSyncTimer for why it runs mid-drag too, and why the first read is discarded).
+    // meterTickMs_ 0 = never ticked.
     instrument::ui::MasterMeterUi masterMeter_;
     unsigned long long meterTickMs_ = 0;