Refactored web server to move route registration into a dedicated method
and extracted static CSS into its own file for better maintainability.
Updated HTML template to use external stylesheet and improved JS code
style consistency. This enhances separation of concerns and prepares
for easier future asset management.
- Integrate Stripe Go SDK and implement a checkout service for creating
Stripe Checkout sessions for a demo product.
- Add request/response types for checkout sessions.
- Create HTTP handler for /api/checkout to initiate sessions via POST.
- Provide comprehensive unit tests for Stripe client and web handler.
- Wire Stripe-backed endpoint in server setup.
