Reflow the deck into two categorical rows plus a double-height MASTER bus deck

Row membership is now the group's own property, not a wrap outcome. FILTER's Band|Notch moves to its caption slack, which is what makes the sound row fit. MASTER gains the limiter toggle, the output meter and the GR lamp.

src/shell/instrument/reasampler_editor.h

@@ -20,6 +20,7 @@
 #include "core/instrument/ui/envelope_overlay.h" // StageEnvelope / EnvNode (envelope overlay draw seam)
 #include "core/instrument/ui/knob_deck.h"        // DeckGroupDesc / DeckLayout (the deck band)
 #include "core/instrument/ui/loop_marks.h"       // LoopMarks (the loop enable's state machine)
+#include "core/instrument/ui/master_meter.h"     // MasterMeterUi (the bus meter's UI-side state)
 #include "core/instrument/ui/sample_bands.h"     // SampleBands (the band-stack allocator)
 #include "core/instrument/ui/waveform_view.h"    // WaveMark / WaveMarks (the overlay's marks)
 #include "core/instrument/ui/spline_edit.h"      // the shared point-editing grammar
@@ -498,6 +499,11 @@ private:
     std::string searchQuery_;             // type-to-filter narrow; "" = no search
     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.
+    instrument::ui::MasterMeterUi masterMeter_;
+    unsigned long long meterTickMs_ = 0;
+
     // Hover state (transient, never persisted).
     HoverTarget hover_;                   // the interactive element under the pointer
 #ifdef _WIN32