Vendor Chatwoot Vue 3 frontend into frontend/

Copy the Chatwoot (v4.14.0) frontend runnable subset into frontend/ for
customization:
- app/javascript/ (Vue SPA: dashboard, widget, sdk, portal, superadmin)
- app/views/ (ERB templates for vite-plugin-ruby entrypoint resolution)
- app/helpers/, app/assets/ (Rails view helpers, static assets)
- enterprise/ (Enterprise edition frontend overlay)
- config/vite.json, vite.config.ts, bin/vite (Vite-Rails toolchain)
- package.json, pnpm-lock.yaml, tailwind/postcss/eslint configs
- Gemfile, Gemfile.lock (vite_rails gem for bin/vite binstub)

Excluded Rails backend: controllers, models, services, jobs, mailers,
policies, db, lib, spec, public, node_modules.

Update references to the new frontend location:
- .gitignore: exclude frontend build artifacts (node_modules, tmp, packs),
  keep frontend/bin/ and frontend/vendor/ via negation
- backend/scripts/parity_frontend_smoke.sh: CHATWOOT_DIR default
  reference/chatwoot -> ../frontend
- backend/scripts/parity_frontend_browser_smoke.mjs: same default update
- AGENTS.md: add frontend section with Rails/Vite coupling notes
- README: architecture tree includes frontend/

frontend/app/javascript/dashboard/helper/AnalyticsHelper/specs/events.spec.js

@@ -0,0 +1,26 @@
+import * as AnalyticsEvents from '../events';
+
+describe('Analytics Events', () => {
+  it('should be frozen', () => {
+    Object.entries(AnalyticsEvents).forEach(([, value]) => {
+      expect(Object.isFrozen(value)).toBe(true);
+    });
+  });
+
+  it('event names should be unique across the board', () => {
+    const allValues = Object.values(AnalyticsEvents).reduce(
+      (acc, curr) => acc.concat(Object.values(curr)),
+      []
+    );
+    const uniqueValues = new Set(allValues);
+    expect(allValues.length).toBe(uniqueValues.size);
+  });
+
+  it('should not allow properties to be modified', () => {
+    Object.values(AnalyticsEvents).forEach(eventsObject => {
+      expect(() => {
+        eventsObject.NEW_PROPERTY = 'new value';
+      }).toThrow();
+    });
+  });
+});