Architecture decisions: files, diagram references, views and panels

- *.archify-decision files: id (unique, words), title, status, date,
  elements, diagrams, supersedes, and prose; parsed, merged and link-checked
  in the model index; diagnostics on the file
- diagrams point at decisions with decisions: [...] on the diagram, nodes
  and edges; stripped before Archify, unknown ids reported, completion,
  hover and go-to-definition for the ids and for elements/diagrams/
  supersedes in decision files
- Decisions panel on the main.archify page; Decisions rail panel under a
  diagram (hover lights up the node or connection); decisions on element
  cards and in the element dialog; decision view for the file, with a
  lost-model note outside a model
- Archify | New Decision… command and template; editor schemas; the three
  New Model examples carry decisions; docs, changelog, 0.8.0

src/views/diagramView.ts

@@ -14,7 +14,7 @@ import { handleWebviewMessage, WebviewMessage } from '../webview/messages';
 import { makeNonce, messagePage, modelPage, prepareDiagramHtml } from '../webview/page';
 import { viewer3dOption, viewerRoots } from '../webview/viewer3d';
 
-import { DIAGRAM_EDITOR_VIEW_TYPE, PREVIEW_VIEW_TYPE, REGISTRY_VIEW_TYPE } from './viewTypes';
+import { DECISION_VIEW_TYPE, DIAGRAM_EDITOR_VIEW_TYPE, PREVIEW_VIEW_TYPE, REGISTRY_VIEW_TYPE } from './viewTypes';
 
 export { DIAGRAM_EDITOR_VIEW_TYPE, PREVIEW_VIEW_TYPE };
 
@@ -66,6 +66,10 @@ class DiagramPreview implements vscode.Disposable {
           void this.openLinked(message.file, REGISTRY_VIEW_TYPE);
           return;
         }
+        if (message.type === 'openDecision') {
+          void this.openLinked(message.file, DECISION_VIEW_TYPE);
+          return;
+        }
         void handleWebviewMessage(message, this.uri, this.panel);
       }),
     );
@@ -200,10 +204,11 @@ class DiagramPreview implements vscode.Disposable {
       viewer3d: viewer3dOption(this.panel.webview, this.context.extensionUri),
       links: Object.fromEntries(prepared.links),
       descriptions: Object.fromEntries(prepared.descriptions),
+      decisions: prepared.decisions,
       model,
     });
     // Nonces differ per render, so compare the renderer output instead.
-    const fingerprint = `${viewerTheme()}\u0000${result.evidenceNotice ?? ''}\u0000${JSON.stringify([model ?? null, [...prepared.links], [...prepared.descriptions]])}\u0000${result.html}`;
+    const fingerprint = `${viewerTheme()}\u0000${result.evidenceNotice ?? ''}\u0000${JSON.stringify([model ?? null, [...prepared.links], [...prepared.descriptions], prepared.decisions])}\u0000${result.html}`;
     if (!force && this.rendered && fingerprint === this.lastHtml) {
       void this.panel.webview.postMessage({ type: 'notice', notice: undefined });
       return;