Play a sound through a graph of gain, pitch and EQ effects #311

A sound could only be played as it was uploaded. A Sound FX asset is
a node graph like a shader: Input, effects, Output. Play sound has a
new input fx that sends the voice through it.

- New asset type soundfx ("Sound FX"), not placeable, with a graph
  and its own tab. The heading in the asset panel is "Sound effects",
  so it does not take the click meant for the + menu entry.
- Nodes in core/soundfx/nodes.ts, category sound, port type audio
  that only fits audio: Input, Output, Gain (dB), Pitch (semitones),
  EQ (80 Hz and 12 kHz shelves, peaks at 250 Hz, 1 kHz and 4 kHz).
- compileSoundFx walks back from the Output with the shared graph
  emitter. An input takes one edge, so the result is one line: a
  pitch and a list of gain and filter stages. A node without input
  or a graph without Output reports a problem on the node.
- Pitch is the playback rate of the source. It applies to the whole
  sound and also changes its length, the node description says so.
- The BehaviorSystem resolves fx and hands the line to the AudioSink.
  An fx that is missing or does not compile plays the sound dry.
- SoundLibrary wires source, stages, volume, destination in that
  order. stats().last now also names pitch and stage count.
- The tab header picks one of the project's sounds and plays it
  through the graph as it stands. Stop there ends only its own voice.

Tests:
- soundfx.test.ts (new, 11), sound-library (9, +2 for the wiring),
  node-catalog (+1 for fx), graph and asset-groups adjusted
- e2e 34: ALL PASSED - 26 checks (+5: + menu opens the tab, palette,
  2 effects, tab Play and game Play through the FX at -12 st)
- Gate on melektaus-atx: typecheck, lint, prettier clean, 239 of 240
  test files green. The red one was sound-library (its fake
  AudioContext had no playbackRate), fixed afterwards, gate not
  re-run in full.
- Counter-check: without the audio rule in portsCompatible the port
  test fails.

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

src/editor/Editor.ts

@@ -72,6 +72,7 @@ import { type PlayHost, PlaySession, type WorldSnapshot } from './PlaySession';
 import { ProjectSession } from './ProjectSession';
 import { ParticlesEditor } from './particles/ParticlesEditor';
 import { ShaderEditor } from './shader/ShaderEditor';
+import { SoundFxEditor } from './soundfx/SoundFxEditor';
 import { StateMachineEditor } from './statemachine/StateMachineEditor';
 import { installShortcuts } from './shortcuts';
 import type { PlayFrom } from '../core/model/playSettings';
@@ -93,6 +94,7 @@ export type CentreTab =
   | 'statemachine'
   | 'shader'
   | 'particles'
+  | 'soundfx'
   | 'game'
   | 'texture'
   | 'vectorart'
@@ -142,6 +144,7 @@ const PANE_ORDER = [
   'statemachine',
   'shader',
   'particles',
+  'soundfx',
   'texture',
   'vectorart',
   'pixelart',
@@ -161,6 +164,7 @@ const TAB_LABELS: Record<CentreTab, string> = {
   statemachine: 'State machine',
   shader: 'Shader',
   particles: 'Particles',
+  soundfx: 'Sound FX',
   texture: 'Texture',
   vectorart: 'Vector art',
   pixelart: 'Pixel art',
@@ -209,6 +213,7 @@ export class Editor implements PlayHost {
   readonly stateMachineEditor: StateMachineEditor;
   readonly shaderEditor: ShaderEditor;
   readonly particlesEditor: ParticlesEditor;
+  readonly soundFxEditor: SoundFxEditor;
   readonly textureEditor: TextureEditor;
   readonly vectorArtEditor: VectorArtEditor;
   readonly pixelArtEditor: PixelArtEditor;
@@ -294,6 +299,7 @@ export class Editor implements PlayHost {
     this.stateMachineEditor = new StateMachineEditor(state);
     this.shaderEditor = new ShaderEditor(state);
     this.particlesEditor = new ParticlesEditor(state);
+    this.soundFxEditor = new SoundFxEditor(state);
     this.textureEditor = new TextureEditor(state);
     this.vectorArtEditor = new VectorArtEditor(state);
     this.pixelArtEditor = new PixelArtEditor(state);
@@ -402,6 +408,7 @@ export class Editor implements PlayHost {
       statemachine: this.stateMachineEditor,
       shader: this.shaderEditor,
       particles: this.particlesEditor,
+      soundfx: this.soundFxEditor,
       texture: this.textureEditor,
       vectorart: this.vectorArtEditor,
       pixelart: this.pixelArtEditor,
@@ -591,6 +598,8 @@ export class Editor implements PlayHost {
         return this.shaderEditor.canvas.paste();
       case 'particles':
         return this.particlesEditor.canvas.paste();
+      case 'soundfx':
+        return this.soundFxEditor.canvas.paste();
       default:
         return false;
     }