Model graph: the whole model as one graph with queries; 0.9.0

- Model | Graph switch on main.archify (Diagram | Graph on diagram pages, narrowed to that diagram)
- union graph of every element and connection, registry and inline, built from the model index
- query box: text, type:, diagram:, decision:, uses:, near:, from: to:, unused, shared, -shared
- side panel per element and connection with diagrams, registry line and decisions one click away
- legend chips, Fit, Layout, Labels, Export PNG; Cytoscape.js bundled as dist/graph.js
- command Archify | Open Model Graph; integration check; unit tests for graph and queries

src/webview/viewer3d.ts

@@ -13,3 +13,8 @@ export function viewer3dOption(webview: vscode.Webview, extensionUri: vscode.Uri
     defaultView,
   };
 }
+
+/** The Graph page script (a webview URI). */
+export function graphScriptUri(webview: vscode.Webview, extensionUri: vscode.Uri): string {
+  return webview.asWebviewUri(vscode.Uri.joinPath(extensionUri, 'dist', 'graph.js')).toString();
+}