feat(mq_editor): replace replicas with harmonics model

- Fundamental f0 always synthesized; harmonics added at n*freq_mult
- decay^n amplitude rolloff per harmonic (capped at 0.90)
- Resonator mode also expanded across harmonics (per-harmonic y1/y2 state)
- UI: h.decay, h.freq (default 2.0), jitter, spread↑/↓ params
- Viewer: faint dotted harmonic bands with spread visualization
- Default freq_mult=2.0 (natural harmonic series)

handoff(Gemini): harmonics model complete, ready for next task

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/tools/mq_editor/app.js b/tools/mq_editor/app.js
index 1e17adf..9df00fb 100644
--- a/tools/mq_editor/app.js
+++ b/tools/mq_editor/app.js
@@ -220,7 +220,9 @@ function loadAudioBuffer(buffer, label) {
       if (!extractedPartials) extractedPartials = [];
       pushUndo();
       const {spread_above, spread_below} = autodetectSpread(partial, stftCache, fftSize, audioBuffer.sampleRate);
-      partial.replicas = { ...partial.replicas, spread_above, spread_below };
+      if (!partial.harmonics) partial.harmonics = { decay: 0.0, freq_mult: 2.0, jitter: 0.05, spread_above: 0.02, spread_below: 0.02 };
+      partial.harmonics.spread_above = spread_above;
+      partial.harmonics.spread_below = spread_below;
       extractedPartials.unshift(partial);
       refreshPartialsView(0);
       setStatus(`${exploreMode}: added partial (${extractedPartials.length} total)`, 'info');
@@ -331,7 +333,7 @@ function createNewPartial() {
       v0: 440,     v1: 440,         v2: 440,          v3: 440,
       a0: 1.0,     a1: 1.0,         a2: 1.0,          a3: 1.0,
     },
-    replicas: { decay_alpha: 0.1, jitter: 0.05, spread_above: 0.02, spread_below: 0.02 },
+    harmonics: { decay: 0.0, freq_mult: 2.0, jitter: 0.05, spread_above: 0.02, spread_below: 0.02 },
   };
   extractedPartials.unshift(newPartial);
   refreshPartialsView(0);
@@ -355,12 +357,12 @@ function autoSpreadAll() {
   if (!extractedPartials || !stftCache) return;
   const fs = stftCache.fftSize;
   const sr = audioBuffer.sampleRate;
-  const defaults = { decay_alpha: 0.1, jitter: 0.05, spread_above: 0.02, spread_below: 0.02 };
+  const defaults = { decay: 0.0, freq_mult: 2.0, jitter: 0.05, spread_above: 0.02, spread_below: 0.02 };
   for (const p of extractedPartials) {
     const {spread_above, spread_below} = autodetectSpread(p, stftCache, fs, sr);
-    if (!p.replicas) p.replicas = { ...defaults };
-    p.replicas.spread_above = spread_above;
-    p.replicas.spread_below = spread_below;
+    if (!p.harmonics) p.harmonics = { ...defaults };
+    p.harmonics.spread_above = spread_above;
+    p.harmonics.spread_below = spread_below;
   }
   if (viewer) viewer.render();
   const sel = viewer ? viewer.selectedPartial : -1;