0.3.0: .archify files are YAML and open straight into the diagram

- .archify content is YAML (JSON still accepted); converted to JSON for the renderer
- Archify Diagram custom editor is the default for *.archify; Show Source opens the YAML beside it
- YAML syntax errors and validation problems mapped to YAML lines
- yamlValidation for schema completion with redhat.vscode-yaml
- scripts/to-yaml.mjs converts existing .archify files

test/renderer.test.ts

@@ -24,7 +24,7 @@ function load(name: string) {
   const text = fs.readFileSync(path.join(fixtures, name), 'utf8');
   const source = readDiagramSource(text, name);
   assert.ok(source, `${name} is a diagram source`);
-  return { ...source, text };
+  return source;
 }
 
 for (const name of fs.readdirSync(fixtures).filter((file) => !file.startsWith('mco-'))) {
@@ -46,7 +46,7 @@ test('reports schema problems with JSON pointer paths', async () => {
 
 test('render failure returns the CLI error', async () => {
   const text = JSON.stringify({ schema_version: 1, diagram_type: 'architecture', meta: {}, components: [] });
-  const result = await renderDiagram(runtime(), { type: 'architecture', diagram: JSON.parse(text), text }, 'fallback');
+  const result = await renderDiagram(runtime(), { type: 'architecture', diagram: JSON.parse(text), format: 'json', json: text }, 'fallback');
   assert.equal(result.ok, false);
   assert.match(result.error ?? '', /schema validation failed/);
 });