feat(mq_editor): global resonator test-mode checkbox in Synthesis panel

Adds "Resonator (all)" checkbox that forces resonator synthesis for all
partials without modifying per-partial mode settings.
Fixes null deref when partial.resonator is undefined in forceResonator mode.

handoff(Gemini): resonator test-mode checkbox added; no per-partial data mutated

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

2 files changed, 8 insertions, 6 deletions

diff --git a/tools/mq_editor/index.html b/tools/mq_editor/index.html
index 81b5bef..61ff1ac 100644
--- a/tools/mq_editor/index.html
+++ b/tools/mq_editor/index.html
@@ -348,6 +348,7 @@
         <label><input type="checkbox" id="integratePhase" checked> Integrate phase</label>
         <label><input type="checkbox" id="disableJitter"> Disable jitter</label>
         <label><input type="checkbox" id="disableSpread"> Disable spread</label>
+        <label title="Test mode: force resonator synthesis for all partials (ignores per-partial mode setting)"><input type="checkbox" id="forceResonator"> Resonator (all)</label>
       </div>
     </div>
   </div>
@@ -627,11 +628,12 @@
       const partialsToUse = extractedPartials.slice(0, keepCount).filter(p => !p.muted);
       setStatus(`Synthesizing ${partialsToUse.length}/${extractedPartials.length} partials (${keepPct.value}%)...`, 'info');
 
-      const integratePhase = document.getElementById('integratePhase').checked;
-      const disableJitter  = document.getElementById('disableJitter').checked;
-      const disableSpread  = document.getElementById('disableSpread').checked;
+      const integratePhase  = document.getElementById('integratePhase').checked;
+      const disableJitter   = document.getElementById('disableJitter').checked;
+      const disableSpread   = document.getElementById('disableSpread').checked;
+      const forceResonator  = document.getElementById('forceResonator').checked;
       const pcm = synthesizeMQ(partialsToUse, audioBuffer.sampleRate, audioBuffer.duration,
-                               integratePhase, {disableJitter, disableSpread});
+                               integratePhase, {disableJitter, disableSpread, forceResonator});
 
       if (viewer) {
         viewer.setSynthStftCache(new STFTCache(pcm, audioBuffer.sampleRate, fftSize, parseInt(hopSize.value)));
diff --git a/tools/mq_editor/mq_synth.js b/tools/mq_editor/mq_synth.js
index f298392..d85c890 100644
--- a/tools/mq_editor/mq_synth.js
+++ b/tools/mq_editor/mq_synth.js
@@ -50,12 +50,12 @@ function synthesizeMQ(partials, sampleRate, duration, integratePhase = true, opt
     const fc = partial.freqCurve;
     const ac = partial.ampCurve;
 
-    if (partial.resonator && partial.resonator.enabled) {
+    if ((partial.resonator && partial.resonator.enabled) || options.forceResonator) {
       // --- Two-pole resonator mode ---
       // Driven by band-limited noise scaled by amp curve.
       // r controls pole radius (bandwidth): r→1 = narrow, r→0 = wide.
       // gainNorm = sqrt(1 - r²) normalises steady-state output power to ~A.
-      const res      = partial.resonator;
+      const res      = partial.resonator || {};
       const r        = res.r        != null ? Math.min(0.9999, Math.max(0, res.r)) : 0.995;
       const gainComp = res.gainComp != null ? res.gainComp : 1.0;
       const gainNorm = Math.sqrt(Math.max(0, 1.0 - r * r));