Route sounds, songs and buses in one Master routing graph (#351)

A project bus could only go into one other bus, and a sound, an
instrument, a pattern or a song into exactly one bus. A shared reverb
needs a sound to go there in part and on dry at the same time. Instead
of a list of sends on every asset, the project gets one routing graph
like the routing of a song (#350), one level up.

- Menu -> Master routing opens a tab with one graph per project. It has
  a node per sound, instrument, pattern, song and bus, named after its
  asset, and one Master. Embedded assets have none, their song routes
  them.
- The nodes follow the assets. Every edit settles the routing in the
  same undo step (KeepRoutingCommand), so an undone delete brings the
  links of its asset back. A new asset gets a node and a link to the
  master. What went only into a deleted bus goes to the master.
- New nodes start in three columns: what plays, the buses, and the
  master a row above, so no link into it runs behind a bus.
- Links are sends: -60 to +12 dB, and a Mode on links out of a bus or a
  song. Out of a sound, an instrument or a pattern a link always takes
  the sound after its volume and FX. Loops are refused.
- A node without a link is silent and says "Goes nowhere".
- The rows Bus and Into are gone. Play nodes with a picked bus still
  overrule the routing.
- A click on a node shows its asset in the inspector, the Master shows
  the master volume and sound FX. A double click opens the asset's tab.
- The graph lives in project.routing and is held to the assets when a
  project is read, but nothing is added there. The editor adds the
  nodes when it opens a project. An asset without a node plays on the
  master, so old projects sound as before without a migration.
- In the mix an asset with one link at 0 dB goes straight into that bus.
  A sound or instrument with more gets a bus of its own with the sends.
  A pattern or song sends from the master of its playing, which is
  where its Mode taps. Buses of the mix can have sends now too.

Found:

- The check "the scheduler plans a looped bar" in e2e 34 wobbles. It
  failed in 2 of 5 runs here and in CI task 580 at 490fcba, before
  this change. HEAD passed it 2 of 2. Not fixed here.

Tests:

- Unit master-routing (new, 10), sound-library (2 new), buses
  rewritten onto the routing, 5 lists without the Bus row. 5 counter
  checks red.
- e2e 34 (melektaus-atx): ALL PASSED, 93 checks (3 new, 2 rewritten).
  Counter check with the Sound tab ignoring the routing: the routing
  check red.
- Gate (melektaus-atx): CHECK EXIT 0, 273 files, 4225 tests.

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

src/editor/Editor.ts

@@ -1,6 +1,6 @@
 import type { Application, Ticker } from 'pixi.js';
 import type { Asset } from '../core/model/Asset';
-import { findAsset, findObjectHolder } from '../core/model/Project';
+import { findAsset, findObjectHolder, ROUTING_ID } from '../core/model/Project';
 import { assetTitle } from '../core/music/embedded';
 import { mixOf } from '../core/music/mixer';
 import type { Role } from '../core/store/AuthStore';
@@ -94,6 +94,7 @@ import type { PluginManager } from './plugins/loader';
 import { PluginsPane } from './plugins/PluginsPane';
 import { ManagementPane } from './users/ManagementPane';
 import { UsersPane } from './users/UsersPane';
+import { RoutingEditor } from './routing/RoutingEditor';
 
 export type CentreTab =
   | 'scene'
@@ -115,6 +116,7 @@ export type CentreTab =
   | 'tile'
   | 'container'
   | 'variables'
+  | 'routing'
   | 'management';
 
 /** A tab a plugin added; the prefix keeps it apart from every built-in one. */
@@ -123,10 +125,10 @@ export type PluginTabId = `plugin:${string}`;
 export type TabId = CentreTab | PluginTabId;
 /**
  * An open document (#171): an asset by its id, or what a Variables tab shows (#252) by its
- * `valuesKey` – as many of those as were opened. The user management (#179) is no document, but it
- * opens and closes like one.
+ * `valuesKey` – as many of those as were opened. The user management (#179) and the master routing
+ * (#351) are no documents, but they open and close like one.
  */
-export type DocumentId = `asset:${string}` | `values:${string}` | 'management';
+export type DocumentId = `asset:${string}` | `values:${string}` | 'routing' | 'management';
 /** The account behind this session; the menu for it sits at the far right of the toolbar. */
 export interface EditorAccount {
   /** Who is signed in – the menu says so, since the toolbar has no room for a second label. */
@@ -144,7 +146,7 @@ export type StripTab = FixedTab | PluginTabId | DocumentId;
 
 type FixedTab = (typeof FIXED_TABS)[number];
 /** The kinds whose documents are assets, each shown by one editor that is pointed at them in turn. */
-type AssetKind = Exclude<CentreTab, FixedTab | 'variables' | 'management'>;
+type AssetKind = Exclude<CentreTab, FixedTab | 'variables' | 'routing' | 'management'>;
 
 const FIXED_TABS = ['scene', 'game'] as const;
 
@@ -168,6 +170,7 @@ const PANE_ORDER = [
   'tile',
   'container',
   'variables',
+  'routing',
   'management',
 ] as const;
 
@@ -192,6 +195,7 @@ const TAB_LABELS: Record<CentreTab, string> = {
   tile: 'Tile',
   container: 'Container',
   variables: 'Variables',
+  routing: 'Master routing',
   management: 'User management',
 };
 
@@ -202,7 +206,7 @@ const FIXED_TAB_ICONS: Partial<Record<FixedTab, string>> = {
 };
 
 function isDocument(tab: StripTab): tab is DocumentId {
-  return tab === 'management' || tab.startsWith('asset:') || tab.startsWith('values:');
+  return tab === 'management' || tab === 'routing' || tab.startsWith('asset:') || tab.startsWith('values:');
 }
 
 const MIN_LEFT_WIDTH = 160;
@@ -245,6 +249,7 @@ export class Editor implements PlayHost {
   readonly tileEditor: TileEditor;
   readonly containerEditor: ContainerEditor;
   readonly variablesEditor: VariablesEditor;
+  readonly routingEditor: RoutingEditor;
   /** What each open Variables tab shows, by its document. */
   private readonly valueTargets = new Map<DocumentId, ValuesTarget>();
   /** The switch per file in `data/plugins/`, in the user management tab (#179). */
@@ -335,6 +340,7 @@ export class Editor implements PlayHost {
     this.tileEditor = new TileEditor(state);
     this.containerEditor = new ContainerEditor(state);
     this.variablesEditor = new VariablesEditor(state);
+    this.routingEditor = new RoutingEditor(state);
     this.hierarchy = new HierarchyPanel(state);
     this.inspector = new Inspector(state);
     this.tilemapPanel = new TilemapPanel(state);
@@ -383,7 +389,10 @@ export class Editor implements PlayHost {
     this.managementPane = new ManagementPane(this.usersPane, this.pluginsPane);
 
     this.toolbar = new Toolbar(state, {
-      openMainMenu: (anchor) => this.projects.openMainMenu(anchor, this.managementEntries()),
+      openMainMenu: (anchor) =>
+        this.projects.openMainMenu(anchor, this.managementEntries(), [
+          { label: 'Master routing', onSelect: () => this.openDocument('routing') },
+        ]),
       togglePlay: () => (state.mode === 'edit' ? this.play.play() : this.play.stop()),
       togglePause: () => this.play.togglePause(),
       openAccountMenu: (anchor) => this.openAccountMenu(anchor, account),
@@ -453,6 +462,7 @@ export class Editor implements PlayHost {
       game: this.gamePane,
       ...this.assetEditors,
       variables: this.variablesEditor,
+      routing: this.routingEditor,
       management: this.managementPane,
     };
     // Following a call goes on in the same tab: the tab changes its document, not its place.
@@ -532,7 +542,8 @@ export class Editor implements PlayHost {
     // creating it) is for – see the `open` event below.
     state.on('selection', () => {
       const s = state.selection;
-      if (s?.kind === 'node' || s?.kind === 'frame' || s?.kind === 'clip' || s?.kind === 'song')
+      if (s?.kind === 'node' && s.assetId === ROUTING_ID) this.openDocument('routing');
+      else if (s?.kind === 'node' || s?.kind === 'frame' || s?.kind === 'clip' || s?.kind === 'song')
         this.openDocument(`asset:${s.assetId}`);
       if (s?.kind === 'object' && findAsset(state.project, s.holderId)?.type === 'container')
         this.openDocument(`asset:${s.holderId}`);
@@ -791,6 +802,7 @@ export class Editor implements PlayHost {
     if (kind && kind in this.assetEditors)
       this.assetEditors[kind as AssetKind].forgetView(doc.slice('asset:'.length));
     this.valueTargets.delete(doc);
+    if (doc === 'routing') this.routingEditor.close();
     if (!wasShowing) return;
     if (this.documents.active) this.showDocument(this.documents.active);
     else this.showTab('scene');
@@ -807,8 +819,8 @@ export class Editor implements PlayHost {
       if (doc) this.openDocument(doc);
       return;
     }
-    if (tab === 'management') {
-      this.openDocument('management');
+    if (tab === 'management' || tab === 'routing') {
+      this.openDocument(tab);
       return;
     }
     if (tab in this.assetEditors) {
@@ -856,7 +868,7 @@ export class Editor implements PlayHost {
       const target = this.valueTargets.get(doc);
       return target && valuesTitle(this.state, target) !== null ? 'variables' : null;
     }
-    if (doc === 'management') return 'management';
+    if (doc === 'management' || doc === 'routing') return doc;
     const type = findAsset(this.state.project, doc.slice('asset:'.length))?.type;
     const kind = type ? TAB_OF_ASSET[type] : undefined;
     return kind && kind !== 'scene' ? kind : null;
@@ -870,12 +882,14 @@ export class Editor implements PlayHost {
     if (kind === 'variables' && target) this.variablesEditor.show(target);
     // Read on every showing: an account may have been changed from another tab in the meantime.
     if (kind === 'management') void this.usersPane?.reload();
+    if (kind === 'routing') this.routingEditor.open();
     this.display(kind, doc);
   }
 
   /** What a document's tab says: the asset's name, or what a Variables tab shows, as its header says. */
   private labelOf(doc: DocumentId): string {
     if (doc === 'management') return this.usersPane ? TAB_LABELS.management : 'Plugins';
+    if (doc === 'routing') return TAB_LABELS.routing;
     const target = this.valueTargets.get(doc);
     if (target) return valuesTitle(this.state, target, this.inspector.liveVariables) ?? '';
     const asset = findAsset(this.state.project, doc.slice('asset:'.length));
@@ -885,6 +899,7 @@ export class Editor implements PlayHost {
   /** The icon in front of a document's name: its asset type's, as in the asset panel. */
   private iconOf(doc: DocumentId): string {
     if (doc === 'management') return this.usersPane ? USERS_ICON_SVG : PLUGINS_ICON_SVG;
+    if (doc === 'routing') return ASSET_ICON_SVG.bus;
     const target = this.valueTargets.get(doc);
     if (target) return target.kind === 'list' ? LIST_ICON_SVG : ASSET_ICON_SVG.variables;
     const type = findAsset(this.state.project, doc.slice('asset:'.length))?.type;
@@ -900,7 +915,7 @@ export class Editor implements PlayHost {
       const kind = this.kindOf(doc);
       if (!this.tabs.has(doc) && kind)
         this.tabs.addTab(doc, this.labelOf(doc), base + index, {
-          kind: doc === 'management' ? this.labelOf(doc) : TAB_LABELS[kind],
+          kind: doc === 'management' || doc === 'routing' ? this.labelOf(doc) : TAB_LABELS[kind],
           icon: this.iconOf(doc),
           onClose: () => this.closeDocument(doc),
         });