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

src/shell/instrument/editor_paint_deck.cpp

@@ -37,11 +37,14 @@ std::string tickLabel(int db) {
 }
 
 // The MASTER column: dB scale in the label gutter, one or two bars, the held peak tick, and
-// the latched clip cap. `split` is waveformSurface's own lane decision — see master_meter.h.
+// the latched clip cap. `split` is the RESOLVED lane decision — see master_meter.h.
 void paintMeterColumn(LICE_IBitmap* bmp, const Rect& column, const MasterMeterUi& state,
                       LaneSplit split) {
     if (column.width <= 0 || column.height <= 0) return;
     const MeterRects m = meterRects(column, split);
+    // A column narrower than the interior needs yields all-empty rects, which under rect.h's
+    // contract means suppressed — not a zero-height field to fill, tick twelve times and cap.
+    if (m.field.empty()) return;
     fillSurface(bmp, toKitBox(m.field), Role::BgCell, InteractionState::Rest);
 
     // Scale: a rule every 6 dB, numeralled every 12 with 0 dB heavier — the reference the
@@ -60,8 +63,9 @@ void paintMeterColumn(LICE_IBitmap* bmp, const Rect& column, const MasterMeterUi
         }
     }
 
-    // The bars. A single-lane surface shows ONE bar off the louder channel: the two are the
-    // same signal there (dual-mono), so two bars would be a duplicate rather than a reading.
+    // The bars. A single-lane surface shows ONE bar folding both channels per field
+    // (meterSingleLaneState) — the two are the same signal there (dual-mono), so two bars would
+    // be a duplicate rather than a reading.
     const LICE_pixel barInk = toLice(roleColor(Role::AccentPrimary));
     const LICE_pixel holdInk = toLice(roleColor(Role::TextPrimary));
     const auto drawBar = [&](const Rect& bar, const instrument::engine::MeterState& ch) {