Add JamesDSP playback controls and verification harness

frontend/jamesdsp-controller.test.js

@@ -96,3 +96,14 @@ test('preset gain and Level gain combine within engine bounds without pausing pl
   assert.equal(f.controller.state().maxLiveHeaps, 1);
   assert.equal(f.controller.active, true);
 });
+
+test('A/B bypass is retained when settings are reapplied', async () => {
+  const f = fixture();
+  await f.controller.enable({ preset: 'warm' }, 0);
+  assert.equal(await f.controller.toggleBypass(), true);
+  await f.controller.enable({ preset: 'bass' }, 0);
+  assert.equal(f.controller.state().bypassed, true);
+  assert.ok(f.bypass.at(-1));
+  assert.equal(await f.controller.toggleBypass(), false);
+  assert.equal(f.bypass.at(-1), false);
+});