feat(mq_editor): UI improvements and partial detection enhancements

- Right panel with synthesis checkboxes (integrate phase, disable jitter, disable spread)
- Style file chooser as button; show filename next to page title
- Second backward pass in extractPartials to recover partial onsets
- Cursor line drawn on overlay canvas (no full redraw on mousemove)

handoff(Claude): UI + algo improvements complete

1 files changed, 6 insertions, 3 deletions

diff --git a/tools/mq_editor/mq_synth.js b/tools/mq_editor/mq_synth.js
index 6fa2a09..1eec709 100644
--- a/tools/mq_editor/mq_synth.js
+++ b/tools/mq_editor/mq_synth.js
@@ -25,10 +25,13 @@ function randFloat(seed, min, max) {
 // replicas: {offsets, decay_alpha, jitter, spread_above, spread_below}
 // integratePhase: true = accumulate 2π*f/SR per sample (correct for varying freq)
 //                 false = 2π*f*t (simpler, only correct for constant freq)
-function synthesizeMQ(partials, sampleRate, duration, integratePhase = true) {
+function synthesizeMQ(partials, sampleRate, duration, integratePhase = true, options = {}) {
   const numSamples = Math.floor(sampleRate * duration);
   const pcm = new Float32Array(numSamples);
 
+  const jitterMult = options.disableJitter ? 0 : 1;
+  const spreadMult = options.disableSpread ? 0 : 1;
+
   const defaultReplicas = {
     offsets:       [1.0],
     decay_alpha:   0.1,
@@ -50,8 +53,8 @@ function synthesizeMQ(partials, sampleRate, duration, integratePhase = true) {
     const replicaData = [];
     for (let r = 0; r < offsets.length; ++r) {
       // Fixed per-replica spread (frequency detuning) and initial phase (jitter)
-      const spread    = randFloat(p * 67890 + r * 999, -spread_below, spread_above);
-      const initPhase = randFloat(p * 67890 + r,        0.0, 1.0) * jitter * 2.0 * Math.PI;
+      const spread    = spreadMult * randFloat(p * 67890 + r * 999, -spread_below, spread_above);
+      const initPhase = randFloat(p * 67890 + r, 0.0, 1.0) * (jitter * jitterMult) * 2.0 * Math.PI;
       replicaData.push({ratio: offsets[r], spread, phase: initPhase});
     }