feat(mq_editor): sort partials by amplitude, keep% slider for reconstruction

- Sort extracted partials by decreasing peak amplitude
- Add Keep% range slider (1-100%) to toolbar
- Viewer draws omitted partials at 50% opacity (live on slider input)
- synthesizeMQ uses only the top-N% partials

handoff(Claude): partial amplitude filtering complete

1 files changed, 11 insertions, 0 deletions

diff --git a/tools/mq_editor/viewer.js b/tools/mq_editor/viewer.js
index 5065498..e8780e7 100644
--- a/tools/mq_editor/viewer.js
+++ b/tools/mq_editor/viewer.js
@@ -30,6 +30,9 @@ class SpectrogramViewer {
     // Tooltip
     this.tooltip = document.getElementById('tooltip');
 
+    // Partial keep count (Infinity = all kept)
+    this.keepCount = Infinity;
+
     // Playhead
     this.playheadTime = -1; // -1 = not playing
 
@@ -59,6 +62,11 @@ class SpectrogramViewer {
     this.render();
   }
 
+  setKeepCount(n) {
+    this.keepCount = n;
+    this.render();
+  }
+
   setFrames(frames) {
     this.frames = frames;
   }
@@ -216,6 +224,7 @@ class SpectrogramViewer {
     for (let p = 0; p < partials.length; ++p) {
       const partial = partials[p];
       const color = colors[p % colors.length];
+      ctx.globalAlpha = p < this.keepCount ? 1.0 : 0.5;
 
       // Draw raw trajectory
       ctx.strokeStyle = color + '44';
@@ -281,6 +290,8 @@ class SpectrogramViewer {
         this.drawControlPoint(curve.t3, curve.v3);
       }
     }
+
+    ctx.globalAlpha = 1.0;
   }
 
   // Render raw peaks from mq_extract (before partial tracking)