feat(editor): master mix strip (mute/solo/fader) in the Tracks pane

CHANGELOG.md

@@ -8,15 +8,19 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- **The master mix can be muted (and soloed, and faded) from the Tracks
+  pane.** The master row used to carry no inline strip — its controls lived
+  only in the mixer drawer. The pane now mirrors the drawer: same M/S/fader,
+  same canonical mix state, and the master keeps its output-bus semantics
+  (its own mute silences it; another track's solo never does).
 - **The master mix is a channel strip in the mixer.** Every audio source now has
   a vertical strip in the mixer drawer — the master mix leads the audio band
   (matching the DAW console), followed by the stems, then the MIDI parts and the
   SOURCE/GUIDE/CLICK/MASTER buses. Its fader, mute, and solo are real: the active
   source's reference playback now routes through its own per-source gain before
   the SOURCE submix, so riding the master strip actually changes its level. The
-  Tracks pane still lists the master as a selectable source row (click it to
-  chart against the full mix), but its strip **controls** — fader, mute, solo —
-  live only in the mixer, not the pane.
+  Tracks pane also exposes the same master fader, mute, and solo controls
+  inline, so the pane and mixer drawer share one canonical mix state.
 - **Click a track to chart against it.** Selecting an audio track (the master
   mix or any stem) in the Tracks column now makes it the **active source**:
   the main waveform shows that track and the onset tools (Suggest, snapping)

src/track-session.js

@@ -338,6 +338,13 @@ export function _trackSessionDensityPure(width) {
     const value = Number(width) || 0;
     return value < 230 ? 'compact' : value < 400 ? 'normal' : 'wide';
 }
+// Which Tracks-pane rows show the inline M/S/fader strip: every row with a
+// mix key — transcription parts, stem audio rows, AND the master mix (its
+// old master-excluded carve-out is gone: the pane mirrors the mixer drawer;
+// see mixControls in render()). Folders have no strip key and never strip.
+export function _trackRowShowsStripPure(row) {
+    return !!(row && row.mixKey);
+}
 // Logic-style auto-fit, deliberately modest: spare viewport height improves
 // readability but the automatic bonus caps at 32px so a two-track song does
 // not turn into two enormous empty slabs. Never shrinks below authored.
@@ -641,16 +648,16 @@ function render() {
     const guideName = guideRow ? guideRow.name
         : ((sources.find(s => s.id === model.tempoGuideSourceId) || sources[0] || {}).name || 'No guide');
     // Per-part M/S/fader — the SAME canonical partMix the mixer panel owns
-    // (band-mode gains ramp off it live). Transcription parts AND stem audio
-    // rows get strips inline here. The MASTER mix is DELIBERATELY excluded from
-    // the left Tracks pane: it lives as a channel strip in the mixer drawer (its
-    // fader/mute/solo are real there — reference playback routes through a
-    // per-source gain, audio.js), and Christian wants the left pane kept to the
-    // tracks themselves, not the master-out or bus mixes.
+    // (band-mode gains ramp off it live). EVERY row with a strip key gets the
+    // inline controls, the master mix included: it used to be deliberately
+    // excluded here (mixer-drawer-only, an early preference), but muting the
+    // master from the pane is a real workflow — dogfooding sessions kept
+    // reaching for it — so the pane now mirrors the drawer. Same keys, same
+    // handlers (mix-mute/mix-solo/mix-vol are key-generic), and the master
+    // keeps its output-bus semantics: its own mute silences it, other tracks'
+    // solo never does (_mixerPartAudiblePure's 'audio:master' carve-out).
     const mixControls = row => {
-        const stripped = row.type === 'transcription'
-            || (row.type === 'audio' && row.sourceKind !== 'master');
-        if (!row.mixKey || !stripped) return '';
+        if (!_trackRowShowsStripPure(row)) return '';
         const key = _editorEscHtml(row.mixKey);
         const st = _mixerPartStatePure(S.partMix, row.mixKey);
         return `<button class="editor-track-ms" data-track-action="mix-mute" data-mix-key="${key}" aria-pressed="${st.mute}" title="Mute track">M</button>`

tests/track_strip_master.test.mjs

@@ -0,0 +1,58 @@
+/*
+ * Tracks-pane strip visibility (src/track-session.js _trackRowShowsStripPure).
+ *
+ * The master mix row now shows the same inline M/S/fader strip as every other
+ * strip-keyed row — its old deliberate carve-out (mixer-drawer-only) is gone.
+ * Pinned here so the master can't silently lose its pane mute again, and so
+ * folders (no strip key) can't grow one.
+ *
+ * Run: node tests/track_strip_master.test.mjs
+ */
+import assert from 'node:assert';
+
+const {
+    _trackRowShowsStripPure,
+    _trackSessionNormalizePure,
+    _trackSessionRowsPure,
+} = await import('../src/track-session.js');
+
+let pass = 0, fail = 0;
+function t(name, fn) {
+    try { fn(); pass++; console.log('  ok   ' + name); }
+    catch (e) { fail++; console.error('  FAIL ' + name + ': ' + e.message); }
+}
+
+const sources = [
+    { id: 'master', name: 'Full Mix', kind: 'master', url: '/full.ogg' },
+    { id: 'Guitar_L', name: 'Guitar_L', kind: 'stem', url: '/s1.ogg' },
+];
+const arrangements = [{ name: 'Lead' }];
+const drumTab = { name: 'Drums', hits: [{ t: 0 }] };
+
+t('the MASTER row shows the strip — the old carve-out is gone', () => {
+    const model = _trackSessionNormalizePure(null, sources, arrangements, drumTab);
+    const { rows } = _trackSessionRowsPure(model, sources, arrangements, drumTab, {});
+    const master = rows.find(r => r.type === 'audio' && r.sourceKind === 'master');
+    assert.ok(master, 'master row exists');
+    assert.strictEqual(master.mixKey, 'audio:master', 'master strips on the output-bus key');
+    assert.strictEqual(_trackRowShowsStripPure(master), true,
+        'master must show M/S/fader in the pane (the fix)');
+});
+
+t('stem audio and transcription rows keep their strips', () => {
+    const model = _trackSessionNormalizePure(null, sources, arrangements, drumTab);
+    const { rows } = _trackSessionRowsPure(model, sources, arrangements, drumTab, {});
+    for (const row of rows.filter(r => r.type !== 'folder')) {
+        assert.strictEqual(_trackRowShowsStripPure(row), true, `${row.id} shows a strip`);
+    }
+});
+
+t('rows without a strip key never strip (folders, malformed rows)', () => {
+    assert.strictEqual(_trackRowShowsStripPure({ type: 'folder', id: 'f1' }), false);
+    assert.strictEqual(_trackRowShowsStripPure({ mixKey: '' }), false);
+    assert.strictEqual(_trackRowShowsStripPure(null), false);
+    assert.strictEqual(_trackRowShowsStripPure(undefined), false);
+});
+
+console.log(`\n${pass} passed, ${fail} failed`);
+process.exit(fail ? 1 : 0);