Model graph: decisions and registry files as nodes

- one node per decision (tag coloured by status) with decides links to its elements and supersedes links
- one node per registry file with defines links to its elements
- own legend chips, side panels (Open decision, Open registry), type:decision and type:registry
- walks and paths follow the diagrams' connections only; attached nodes follow their elements into a result

src/model/graph.ts

@@ -8,8 +8,13 @@ import { DecisionAttachment, DiagramSummary, ModelMeta, Registry } from './forma
  * the webview bundle and the unit tests share it.
  */
 
+export type GraphNodeKind = 'element' | 'decision' | 'registry';
+export type GraphEdgeKind = 'connection' | 'decides' | 'defines' | 'supersedes';
+
 export interface GraphNode {
   id: string;
+  /** An element of the model, a decision (`decision:<id>`) or a registry file (`registry:<file>`). */
+  kind: GraphNodeKind;
   label: string;
   sublabel?: string;
   type?: string;
@@ -26,11 +31,17 @@ export interface GraphNode {
   diagrams: string[];
   /** Decisions about it: named by the decision, or attached to its node in a diagram. */
   decisions: string[];
+  /** Decision nodes: the effective status. */
+  status?: string;
+  /** Registry nodes: ids of the elements the file defines. */
+  elements?: string[];
 }
 
 export interface GraphEdge {
   /** `from>to`, unique in the graph. */
   id: string;
+  /** A connection drawn by a diagram, or a link to a decision or registry node. */
+  kind: GraphEdgeKind;
   from: string;
   to: string;
   /** Distinct labels the diagrams give this connection. */
@@ -69,6 +80,8 @@ export interface GraphInput {
 }
 
 export const edgeId = (from: string, to: string): string => `${from}>${to}`;
+export const decisionNodeId = (id: string): string => `decision:${id}`;
+export const registryNodeId = (file: string): string => `registry:${file}`;
 
 function pushUnique(list: string[], value: string): void {
   if (!list.includes(value)) list.push(value);
@@ -82,6 +95,7 @@ export function buildGraph(input: GraphInput): ModelGraph {
   for (const e of input.registry.elements.values()) {
     nodes.set(e.id, {
       id: e.id,
+      kind: 'element',
       label: e.label ?? e.id,
       sublabel: e.sublabel,
       type: e.type,
@@ -104,7 +118,7 @@ export function buildGraph(input: GraphInput): ModelGraph {
         const element = n.ref ? input.registry.elements.get(n.ref) : undefined;
         node = element
           ? { ...nodes.get(element.id)!, id: n.id, label: n.label ?? element.label ?? n.id, sublabel: n.sublabel ?? element.sublabel, diagrams: [], decisions: [] }
-          : { id: n.id, label: n.label ?? n.ref ?? n.id, sublabel: n.sublabel, type: n.type, brand: n.brand, shared: false, diagrams: [], decisions: [] };
+          : { id: n.id, kind: 'element', label: n.label ?? n.ref ?? n.id, sublabel: n.sublabel, type: n.type, brand: n.brand, shared: false, diagrams: [], decisions: [] };
         nodes.set(n.id, node);
       }
       pushUnique(node.diagrams, d.relativePath);
@@ -113,7 +127,7 @@ export function buildGraph(input: GraphInput): ModelGraph {
       const id = edgeId(e.from, e.to);
       let edge = edges.get(id);
       if (!edge) {
-        edge = { id, from: e.from, to: e.to, labels: [], diagrams: [], decisions: [] };
+        edge = { id, kind: 'connection', from: e.from, to: e.to, labels: [], diagrams: [], decisions: [] };
         edges.set(id, edge);
       }
       if (e.label) pushUnique(edge.labels, e.label);
@@ -137,6 +151,41 @@ export function buildGraph(input: GraphInput): ModelGraph {
   }
 
   const decisionRow = (d: Decision): GraphDecision => ({ id: d.id, title: d.title, status: effectiveStatus(d, all).status, file: d.file });
+
+  // Registry files as nodes, each linked to the elements it defines.
+  const byFile = new Map<string, string[]>();
+  for (const e of input.registry.elements.values()) byFile.set(e.file, [...(byFile.get(e.file) ?? []), e.id]);
+  for (const file of input.registry.files) if (!byFile.has(file)) byFile.set(file, []);
+  for (const [file, ids] of byFile) {
+    const id = registryNodeId(file);
+    nodes.set(id, { id, kind: 'registry', label: file.replace(/\.archify-registry$/, ''), type: 'registry', shared: true, file, diagrams: [], decisions: [], elements: ids });
+    for (const element of ids) {
+      const edge = edgeId(id, element);
+      edges.set(edge, { id: edge, kind: 'defines', from: id, to: element, labels: [], diagrams: [], decisions: [] });
+    }
+  }
+
+  // Decisions as nodes, linked to the elements and connections they are about, and to what they supersede.
+  for (const d of all.values()) {
+    const id = decisionNodeId(d.id);
+    const row = decisionRow(d);
+    nodes.set(id, { id, kind: 'decision', label: d.title ?? d.id, sublabel: d.id, type: 'decision', shared: true, description: [d.context, d.decision].filter(Boolean).join('\n\n') || undefined, file: d.file, line: 0, diagrams: [...d.diagrams], decisions: [], status: row.status });
+  }
+  for (const node of [...nodes.values()]) {
+    if (node.kind !== 'element') continue;
+    for (const decision of node.decisions) {
+      if (!all.has(decision)) continue;
+      const edge = edgeId(decisionNodeId(decision), node.id);
+      edges.set(edge, { id: edge, kind: 'decides', from: decisionNodeId(decision), to: node.id, labels: [], diagrams: [], decisions: [] });
+    }
+  }
+  for (const d of all.values()) {
+    for (const other of d.supersedes) {
+      if (!all.has(other)) continue;
+      const edge = edgeId(decisionNodeId(d.id), decisionNodeId(other));
+      edges.set(edge, { id: edge, kind: 'supersedes', from: decisionNodeId(d.id), to: decisionNodeId(other), labels: ['supersedes'], diagrams: [], decisions: [] });
+    }
+  }
   return {
     meta: input.meta,
     nodes: [...nodes.values()].sort((a, b) => a.id.localeCompare(b.id)),