feat: setup frontend project with bun and dynamic data fetching

- Create new frontend project directory with Next.js 15 + React 19
- Migrate from pnpm to bun for faster package management
- Add TanStack Query + Axios for dynamic data fetching
- Create comprehensive Makefile with development commands
- Setup API layer with query hooks and error handling
- Configure environment variables and bun settings
- Add TypeScript type checking and project documentation
- Update CLAUDE.md with bun-specific development workflow

frontend/components/loading-spinner.tsx

@@ -0,0 +1,17 @@
+"use client"
+
+import { Camera } from "lucide-react"
+
+export function LoadingSpinner() {
+  return (
+    <div className="min-h-screen bg-white flex items-center justify-center">
+      <div className="text-center">
+        <div className="relative">
+          <Camera className="h-16 w-16 text-gray-400 mx-auto mb-4 animate-pulse" />
+          <div className="absolute inset-0 rounded-full border-2 border-gray-200 border-t-gray-400 animate-spin"></div>
+        </div>
+        <p className="text-gray-600 font-light">加载中...</p>
+      </div>
+    </div>
+  )
+}