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/components-next/copilot/CopilotThinkingBlock.vue

@@ -0,0 +1,25 @@
+<script setup>
+import Icon from '../../components-next/icon/Icon.vue';
+defineProps({
+  content: {
+    type: String,
+    required: true,
+  },
+});
+</script>
+
+<template>
+  <div
+    class="flex flex-col gap-2 p-3 rounded-lg bg-n-background/50 border border-n-weak hover:bg-n-background/80 transition-colors duration-200"
+  >
+    <div class="flex items-start gap-2">
+      <Icon
+        icon="i-lucide-sparkles"
+        class="w-4 h-4 mt-0.5 flex-shrink-0 text-n-slate-9"
+      />
+      <div class="text-sm text-n-slate-12">
+        {{ content }}
+      </div>
+    </div>
+  </div>
+</template>