Convert to React and add comprehensive test suite

- Convert vanilla HTML/JS to React component with hooks
- Add Astro React integration and Node adapter
- Add Vitest with React Testing Library for testing
- Add 55 tests covering API endpoint and UI component
- Add GitHub Actions CI workflow for tests and build
- Update .gitignore for AI assistant directories

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: nhnt11

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npm run test:run
+
+      - name: Build
+        run: npm run build

.gitignore

@@ -24,6 +24,12 @@ dist/
 *.swp
 *.swo
 
+# AI assistants
+.agent/
+.claude/
+.cursor/
+.gemini/
+
 # Debug
 npm-debug.log*
 yarn-debug.log*

astro.config.mjs

@@ -1,5 +1,9 @@
 import { defineConfig } from 'astro/config';
+import react from '@astrojs/react';
+import node from '@astrojs/node';
 
 export default defineConfig({
-  output: 'server'
+  output: 'server',
+  adapter: node({ mode: 'standalone' }),
+  integrations: [react()],
 });