Play every tab's preview straight into the master (#368)

Since #351 the tabs played their asset along its links in the Master
routing, as the game does. A song linked into a reverb bus was heard
through that bus while it was edited. A preview should sound like the
asset itself, so the tabs leave the Master routing out again.

- The Sound, Sound FX, Instrument, Pattern and Song tab play into the
  master. The sound FX of the asset still applies, and so does the
  master's own volume and FX.
- Inside a song its own routing of tracks and sends still counts.
- The game is unchanged: Play nodes go along the routing as before.

Tests:
- e2e 34 (melektaus-atx): ALL PASSED, 96 checks. The routing check
  now holds the mix of the two buses as before, and the Sound tab on
  the master with the bus silent.
- Counter-probe e2e: the Sound tab along the routing again, the
  routing check red.
- Gate (melektaus-atx): CHECK EXIT 0, 274 files, 4230 tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/editor/instrument/InstrumentEditor.ts

@@ -21,8 +21,9 @@ import {
 import { MIDDLE_C, noteName } from '../../core/instrument/notes';
 import type { Asset, InstrumentAsset } from '../../core/model/Asset';
 import { fxVoiceOf } from '../../core/music/needs';
+import { MASTER_MIX } from '../../core/music/mixer';
 import { DEFAULT_TEMPO } from '../../core/music/time';
-import { instrumentBus, instrumentFx, playNote } from '../../runtime/systems/behaviorContext';
+import { instrumentFx, playNote } from '../../runtime/systems/behaviorContext';
 import {
   Button,
   Dropdown,
@@ -168,7 +169,8 @@ export class InstrumentEditor extends AssetTabEditor<InstrumentAsset, GraphCanva
       struck,
       PREVIEW_OWNER,
       { ...this.values },
-      { bus: instrumentBus(this.state.project, asset.id, '') },
+      // Straight into the master: a preview leaves the routing of the instrument out (#368).
+      { bus: MASTER_MIX },
       fxVoiceOf(this.state.project, instrumentFx(this.state.project, asset.id, ''), DEFAULT_TEMPO),
     );
     if (voice) this.voices.push(voice);

src/editor/pattern/PatternEditor.ts

@@ -24,7 +24,7 @@ import { DEFAULT_TEMPO } from '../../core/music/time';
 import { instrumentFx, playNote } from '../../runtime/systems/behaviorContext';
 import { Button, Dropdown, Label, Menu, type Widget } from '../../ui';
 import { Music } from '../../viewport/music';
-import { playedRoute } from '../../core/music/mixer';
+import { MASTER_MIX } from '../../core/music/mixer';
 import { soundLibrary } from '../../viewport/SoundLibrary';
 import { AssetTabEditor } from '../AssetTabEditor';
 import { claimTransport, releaseTransport } from '../music/transport';
@@ -54,10 +54,10 @@ export class PatternEditor extends AssetTabEditor<PatternAsset, PianoRoll> {
   readonly ghostsButton: Button;
   /** Where the ghost notes come from: song, track and bar. */
   readonly ghostSource = new Label('', { style: 'muted' });
-  /** Heard through the sound FX (#352) and along the routing of the asset (#351), as in the game. */
+  /** Heard through the sound FX (#352), then straight into the master: a preview leaves the routing out (#368). */
   readonly music = new Music(
     () => this.state.project,
-    () => playedRoute(this.state.project, '', this.asset()?.id ?? ''),
+    () => MASTER_MIX,
     () => {
       const asset = this.asset();
       return asset && fxVoiceOf(this.state.project, assetFxOf(asset.props), patternTempo(asset.props));

src/editor/song/SongEditor.ts

@@ -28,7 +28,7 @@ import { assetFxOf } from '../../core/properties/assetFx';
 import type { SoundStore } from '../../core/store/SoundStore';
 import { Button, Dialog, Dropdown, Label, Menu, ui, VStack, type Widget } from '../../ui';
 import { Music } from '../../viewport/music';
-import { playedRoute } from '../../core/music/mixer';
+import { MASTER_MIX } from '../../core/music/mixer';
 import { soundLibrary } from '../../viewport/SoundLibrary';
 import {
   type InputDevice,
@@ -93,10 +93,10 @@ export class SongEditor extends AssetTabEditor<SongAsset, SongTimeline> {
   readonly snap = new SnapToggle(() => this.routing);
   private shown: SongView = 'timeline';
   private readonly pane = new VStack();
-  /** Heard through the sound FX (#352) and along the routing of the asset (#351), as in the game. */
+  /** Heard through the sound FX (#352), then straight into the master: a preview leaves the routing out (#368). */
   readonly music = new Music(
     () => this.state.project,
-    () => playedRoute(this.state.project, '', this.asset()?.id ?? ''),
+    () => MASTER_MIX,
     () => {
       const asset = this.asset();
       return asset && fxVoiceOf(this.state.project, assetFxOf(asset.props), songTempo(asset.props));

src/editor/sound/SoundEditor.ts

@@ -16,7 +16,7 @@ import {
 } from '../../core/properties/sounds';
 import { Button, Dropdown, Label, Menu, NumberField } from '../../ui';
 import { soundLibrary } from '../../viewport/SoundLibrary';
-import { playedBus } from '../../core/music/mixer';
+import { MASTER_MIX } from '../../core/music/mixer';
 import { DRY_VOICE } from '../../core/soundfx/nodes';
 import { fxVoiceOf } from '../../core/music/needs';
 import { DEFAULT_TEMPO } from '../../core/music/time';
@@ -152,11 +152,10 @@ export class SoundEditor extends AssetTabEditor<SoundAsset, WaveCanvas> {
     this.stop();
     claimTransport(this.halt);
     const props = resolveAssetProps(this.state.project, asset);
-    // Through its sound FX (#352) and along its routing (#351), as the game hears it.
-    const bus = playedBus(this.state.project, '', asset.id);
+    // Through its sound FX (#352), then straight into the master: a preview leaves its routing out (#368).
     const fx = fxVoiceOf(this.state.project, assetFxOf(props), DEFAULT_TEMPO) ?? DRY_VOICE;
     const file = playedSoundOf({ asset, clip });
-    this.voice = soundLibrary.play(file, volumeOf(props), false, PREVIEW_OWNER, fx, bus);
+    this.voice = soundLibrary.play(file, volumeOf(props), false, PREVIEW_OWNER, fx, MASTER_MIX);
     this.playingId = this.voice ? `${asset.id}:${clip?.id ?? ''}` : '';
     this.syncPlayButton();
   }

src/editor/soundfx/SoundFxEditor.ts

@@ -7,7 +7,7 @@ import { volumeOf } from '../../core/properties/sounds';
 import { soundFxBuildFor, soundFxParams } from '../../core/soundfx/compile';
 import { Button, Dropdown, HStack, Label, Menu, NumberField, Stack, Theme } from '../../ui';
 import { soundLibrary } from '../../viewport/SoundLibrary';
-import { playedBus } from '../../core/music/mixer';
+import { MASTER_MIX } from '../../core/music/mixer';
 import { AssetTabEditor } from '../AssetTabEditor';
 import { GraphCanvas } from '../graph/GraphCanvas';
 import { SnapToggle } from '../graph/SnapToggle';
@@ -106,10 +106,9 @@ export class SoundFxEditor extends AssetTabEditor<SoundFxAsset, GraphCanvas> {
     if (!sound?.asset.file || !plan) return;
     const props = resolveAssetProps(this.state.project, sound.asset);
     const fx = { plan, params: { ...this.values } };
-    // Along the routing of the sound, as the game would play it there (#351).
-    const bus = playedBus(this.state.project, '', sound.asset.id);
+    // Straight into the master: a preview leaves the routing of the sound out (#368).
     const file = playedSoundOf(sound);
-    const voice = soundLibrary.play(file, volumeOf(props), false, PREVIEW_OWNER, fx, bus);
+    const voice = soundLibrary.play(file, volumeOf(props), false, PREVIEW_OWNER, fx, MASTER_MIX);
     if (voice) this.voices.push(voice);
     this.playedFor = asset.id;
   }

src/viewport/music.ts

@@ -52,8 +52,8 @@ export class Music {
   readonly clips: PlannedClip[] = [];
 
   /**
-   * `output` is where what it plays goes (#351): along the routing of the pattern or song in the
-   * tab, so it sounds as it would in the game. The master where left out. `fx` is the sound FX of
+   * `output` is where what it plays goes (#351): the master where left out, as for the preview of
+   * a tab, which leaves the routing of its pattern or song out (#368). `fx` is the sound FX of
    * that pattern or song (#352), on the way there.
    */
   constructor(