feat: Initialize customer-spa project structure

Sprint 1 - Foundation Setup:

Created customer-spa/ folder structure:
```
customer-spa/
├── src/
│   ├── pages/          # Customer pages (Shop, Cart, Checkout, Account)
│   ├── components/     # Reusable components
│   ├── lib/
│   │   ├── api/        # API client
│   │   ├── cart/       # Cart state management
│   │   ├── checkout/   # Checkout logic
│   │   └── tracking/   # Analytics & pixel tracking
│   ├── hooks/          # Custom React hooks
│   ├── contexts/       # React contexts
│   └── types/          # TypeScript types
├── public/             # Static assets
├── package.json        # Dependencies
├── vite.config.ts      # Vite configuration (port 5174)
├── tsconfig.json       # TypeScript configuration
├── tailwind.config.js  # TailwindCSS configuration
├── postcss.config.js   # PostCSS configuration
└── .eslintrc.cjs       # ESLint configuration
```

Configuration:
✅ Vite dev server on port 5174 (admin-spa uses 5173)
✅ HTTPS with shared SSL cert
✅ TypeScript + React 18
✅ TailwindCSS + shadcn/ui
✅ React Query for data fetching
✅ Zustand for state management
✅ React Hook Form + Zod for forms
✅ React Router for routing

Dependencies Added:
- Core: React 18, React DOM, React Router
- UI: Radix UI components, Lucide icons
- State: Zustand, TanStack Query
- Forms: React Hook Form, Zod, @hookform/resolvers
- Styling: TailwindCSS, class-variance-authority
- Utils: clsx, tailwind-merge, sonner (toast)

Next Steps:
- Create main.tsx entry point
- Create App.tsx with routing
- Create base layout components
- Setup API client
- Implement cart state management

Ready for Sprint 1 implementation!

customer-spa/tsconfig.json

@@ -0,0 +1,20 @@
+{
+    "compilerOptions": {
+      "target": "ES2020",
+      "useDefineForClassFields": true,
+      "lib": ["ES2020", "DOM", "DOM.Iterable"],
+      "module": "ESNext",
+      "skipLibCheck": true,
+      "moduleResolution": "Bundler",
+      "resolveJsonModule": true,
+      "isolatedModules": true,
+      "jsx": "react-jsx",
+      "noEmit": true,
+      "strict": true,
+      "allowJs": false,
+      "types": [],
+      "baseUrl": ".",
+      "paths": { "@/*": ["./src/*"] }
+    },
+    "include": ["src"]
+}