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/messages.ts

@@ -12,6 +12,8 @@ export type WebviewMessage =
   | { type: 'openDiagram'; path: string }
   | { type: 'openRegistry'; file: string; line?: number }
   | { type: 'openDecision'; file: string }
+  | { type: 'showGraph'; query?: string }
+  | { type: 'showModel' }
   | { type: 'error'; message: string };
 
 /** Column for opening files next to a webview without covering it. */
@@ -96,6 +98,8 @@ export async function handleWebviewMessage(
         break;
       case 'hash':
       case 'openDiagram':
+      case 'showGraph':
+      case 'showModel':
         // Handled by the view, which knows the model root.
         break;
     }