Give sounds, instruments, patterns and songs a sound FX (#352)

A sound FX could only be picked where something was played: on a Play
node, a track or an item of a song. A sound that should always sound
through the same effect needed that pick everywhere it was used. Now
the asset says it once, and every place that plays it follows.

- New row Sound FX on a sound, an instrument, a pattern and a song,
  right before Bus. A sound goes through it on every voice, an
  instrument on every note after its graph, a pattern on all its
  notes together and a song on its output.
- The fx input of Play sound, Play note, Play pattern and Play song
  and the Sound FX of a song item now read "From the asset" while
  empty. None is a pick of its own, stored as `#none` like `#master`.
  A pick replaces the FX of the asset, it does not come on top.
- A pattern item's Instrument reads "From the asset" instead of None.
  The meaning is unchanged.
- A double-click on a sound item opens the sound, as one on a pattern
  item opens the pattern.
- The tabs play through the FX of their asset. The Pattern and Song
  tab put it on a bus of their own between the output and the bus of
  the asset. The keys of the Pattern tab play there too.
- Notes of a pattern or song go through the FX of their instrument.
  Its chain is loaded with the other needs of the sequence.

Decided without asking:
- Old items and Play nodes with an empty fx now mean "From the
  asset". No asset has an FX yet, so nothing sounds different.
- The label is "From the asset" as on Loop and Bus, not "From asset".
- A sound used as a Sample, as the impulse of a Reverb or as the test
  sound of the Sound FX tab plays without its own FX.

Findings:
- In e2e, `__gm.inspectorField('Sound FX')` and `('Instrument')` find
  the group of the Assets panel first. The check asks for the last
  match.

Tests:
- Unit asset-fx (new): 8 green. Six counter-checks each turned red.
- Field lists of sound, pattern and song: Sound FX added.
- e2e 65 (melektaus-atx): ALL PASSED, 46 checks (3 new). Counter-check
  without the FX bus of the tab: that check red.
- Gate (melektaus-atx): CHECK EXIT 0, 268 files, 4142 tests.
- Not checked: how it sounds, the Sound, Instrument and Pattern tab
  in the browser.

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

src/core/graph/nodes/shared.ts

@@ -94,12 +94,23 @@ export const soundPort = (): PortDef => ({
   field: { key: 'sound', label: 'Sound', kind: 'sound', default: '' },
 });
 
-/** The `fx` input of `Play sound` (#311); unconnected, it shows the picker of sound FX assets. */
+/**
+ * The `fx` input of a Play node (#311); unconnected, it shows the picker of sound FX assets. Empty is
+ * the one its asset names, `NO_FX` none (#352).
+ */
 export const soundFxPort = (): PortDef => ({
   key: 'fx',
   label: 'fx',
   type: 'string',
-  field: { key: 'fx', label: 'FX', kind: 'asset', default: '', assetTypes: ['soundfx'] },
+  field: {
+    key: 'fx',
+    label: 'FX',
+    kind: 'asset',
+    default: '',
+    assetTypes: ['soundfx'],
+    none: 'From the asset',
+    noFx: true,
+  },
 });
 
 /**