feat: introduce archify skill for generating architecture diagrams

- Added a new Archify skill, enabling users to create polished architecture, workflow, sequence, data-flow, and lifecycle diagrams.
- Implemented comprehensive functionality including rendering, validation, and delivery of diagrams in various formats.
- Integrated a user-friendly command-line interface for generating and previewing diagrams.
- Developed supporting files including package.json, LICENSE, and SKILL.md for documentation and licensing.
- Added unit tests to ensure reliability and functionality of the new skill.

These changes enhance the application by providing a structured approach to visualizing system architecture and workflows, improving user experience and data representation.

.agents/skills/archify/test/repository-language-metadata.test.mjs

@@ -0,0 +1,52 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { execFileSync } from 'node:child_process';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const repoRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '../..');
+
+function linguistGenerated(relativePath) {
+  const output = execFileSync(
+    'git',
+    ['check-attr', 'linguist-generated', '--', relativePath],
+    { cwd: repoRoot, encoding: 'utf8' },
+  ).trim();
+  return output.slice(output.lastIndexOf(':') + 1).trim();
+}
+
+test('repository language metadata separates generated artifacts from implementation source', () => {
+  for (const generatedPath of [
+    'archify/examples/web-app-rendered.html',
+    'examples/web-app.html',
+    'docs/cases/mco-runtime.architecture.html',
+    'docs/gallery.html',
+    'docs/gallery/artifacts/web-app.architecture.html',
+    'docs/guide.html',
+    'docs/start.html',
+    'experiments/mco-showcase/mco-runtime.html',
+    'archify/renderers/shared/generated-brand-marks.mjs',
+    'archify/renderers/shared/generated-validators.mjs',
+  ]) {
+    assert.equal(
+      linguistGenerated(generatedPath),
+      'true',
+      `${generatedPath} must be excluded from GitHub language statistics`,
+    );
+  }
+
+  for (const sourcePath of [
+    'archify/assets/template.html',
+    'scripts/gallery-template.html',
+    'scripts/guide-template.html',
+    'scripts/start-template.html',
+    'docs/index.html',
+    'archify/renderers/shared/geometry.mjs',
+  ]) {
+    assert.equal(
+      linguistGenerated(sourcePath),
+      'unspecified',
+      `${sourcePath} must remain visible as implementation source`,
+    );
+  }
+});