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/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));