Edit a Parametric EQ in a tab of its own (#370)

The EQ's editor floated over the editor as a window since #367. The
user wants it as a tab for now. Whether any tab can float and dock
again is weighed apart from this.

- A double-click on the node asks for the tab through
  `EditorState.openEq`, as `openValues` does for a Variables tab.
- The tab is a document `eq:<asset>:<node>`, one per EQ node. A
  second double-click brings the open one up.
- Its name is the asset's, with `EQ 2`, `EQ 3` when the asset has
  more than one. The icon is the sound FX's.
- The tab closes with its node, its asset, or a new project, through
  the same `syncDocuments` as every document.
- `EqWindow` becomes `EqEditor`, a `VStack` with a `TabHeader`. The
  curve takes the room of the tab, 320 x 160 at least.
- The window's title bar, dragging and Close button are gone.
- Delete in the EQ's tab removes the picked band. It never falls
  through to the selection, which is still the EQ's node.
- The hint below the curve is shorter, it was cut off at 1280 px.

Tests:
- e2e 34 (melektaus-atx): ALL PASSED, 96 checks, 2 rewritten. The
  tab opens on a double-click and goes with its node.
- Gate (melektaus-atx): CHECK EXIT 0, 274 files, 4231 tests.

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

src/editor/graph/GraphCanvas.ts

@@ -31,7 +31,6 @@ import { particleLibrary } from '../../viewport/ParticleLibrary';
 import { shaderLibrary } from '../../viewport/ShaderLibrary';
 import { soundFxBuildFor } from '../../core/soundfx/compile';
 import { SoundFxParametricEq } from '../../core/soundfx/nodes';
-import { openEqEditor } from '../soundfx/EqEditor';
 import { instrumentCheck, instrumentSourcesOf } from '../../core/instrument/compile';
 import { masterRoutingProblems } from '../../core/music/projectRouting';
 import { routingProblems } from '../../core/music/routing';
@@ -672,7 +671,7 @@ export class GraphCanvas extends Widget {
 
   private openCalledBehavior(node: GraphNode): boolean {
     if (node.type === SoundFxParametricEq.type) {
-      openEqEditor(this.state, this.assetId, node.id);
+      this.state.openEq(this.assetId, node.id);
       return true;
     }
     // A node of the master routing (#351) stands for its asset; a bus has no tab, its node shows it already.