Add ember-best-practices skill

.agents/skills/ember-best-practices/rules/bundle-embroider-static.md

@@ -0,0 +1,69 @@
+---
+title: Use Embroider Build Pipeline
+impact: CRITICAL
+impactDescription: Modern build system with better performance
+tags: bundle, embroider, build-performance, vite
+---
+
+## Use Embroider Build Pipeline
+
+Use Embroider, Ember's modern build pipeline, with Vite for faster builds, better tree-shaking, and smaller bundles.
+
+**Incorrect (classic build pipeline):**
+
+```javascript
+// ember-cli-build.js
+const EmberApp = require('ember-cli/lib/broccoli/ember-app');
+
+module.exports = function (defaults) {
+  const app = new EmberApp(defaults, {});
+  return app.toTree();
+};
+```
+
+**Correct (Embroider with Vite):**
+
+```javascript
+// ember-cli-build.js
+const EmberApp = require('ember-cli/lib/broccoli/ember-app');
+const { compatBuild } = require('@embroider/compat');
+
+module.exports = async function (defaults) {
+  const { buildOnce } = await import('@embroider/vite');
+
+  let app = new EmberApp(defaults, {
+    // Add options here
+  });
+
+  return compatBuild(app, buildOnce);
+};
+```
+
+**For stricter static analysis (optimized mode):**
+
+```javascript
+// ember-cli-build.js
+const EmberApp = require('ember-cli/lib/broccoli/ember-app');
+const { compatBuild } = require('@embroider/compat');
+
+module.exports = async function (defaults) {
+  const { buildOnce } = await import('@embroider/vite');
+
+  let app = new EmberApp(defaults, {
+    // Add options here
+  });
+
+  return compatBuild(app, buildOnce, {
+    // Enable static analysis for better tree-shaking
+    staticAddonTestSupportTrees: true,
+    staticAddonTrees: true,
+    staticHelpers: true,
+    staticModifiers: true,
+    staticComponents: true,
+  });
+};
+```
+
+Embroider provides a modern build pipeline with Vite that offers faster builds and better optimization compared to the classic Ember CLI build system.
+
+Reference: [Embroider Documentation](https://github.com/embroider-build/embroider)