Migrate from Vue2 to React with modern tech stack

- Replace Vue2 + Vue CLI with Vite + React 18 + TypeScript
- Add Tailwind CSS for efficient styling
- Implement clean component architecture:
  - Split 1000+ line Vue component into focused React components
  - Add proper type safety with TypeScript
  - Use React Query for efficient data fetching
- Update GitHub Actions for React build pipeline
- Maintain existing functionality and design
- Support Node.js 23 with .nvmrc

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.github/workflows/gh-pages.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
     - main
+    - react-migration
 
 jobs:
   build-deploy:
@@ -12,19 +13,17 @@ jobs:
     - uses: actions/checkout@v4
     - uses: actions/setup-node@v4
       with:
-        node-version: 16
-        ref: main
-        submodules: true
+        node-version: 23
+        ref: ${{ github.ref }}
         fetch-depth: 0
     - run: |
-           npm install -g yarn@1.22.19  # ← yarn 1系を使う！
-           yarn install --frozen-lockfile --ignore-engines
+           npm install
 
     - name: Build
       env: 
         TZ: "Asia/Tokyo"
       run: |
-           yarn build
+           npm run build
 
     - name: Deploy
       uses: peaceiris/actions-gh-pages@v3