feat(payments): implement student ticket payment flow with Paystack integration

.env.example

@@ -0,0 +1,12 @@
+# Server-only Paystack secret. Never expose this with a NEXT_PUBLIC_ prefix.
+PAYSTACK_SECRET_KEY=sk_test_replace_me
+
+# Student ticket settings. The price is entered in whole Kenyan shillings.
+STUDENT_TICKET_PRICE_KES=1000
+STUDENT_TICKET_CURRENCY=KES
+STUDENT_TICKET_SALES_ENABLED=false
+STUDENT_EMAIL_DOMAIN_SUFFIXES=ac.ke,edu
+# Optional comma-separated additions to the built-in public provider blocklist.
+STUDENT_EMAIL_BLOCKED_DOMAINS=
+
+NEXT_PUBLIC_BASE_URL=http://localhost:3000

.gitignore

@@ -31,6 +31,7 @@ yarn-error.log*
 
 # env files (can opt-in for committing if needed)
 .env*
+!.env.example
 
 # vercel
 .vercel

README.md

@@ -13,3 +13,33 @@ bun dev
 Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.
 
 You can start editing the page by modifying `src/app/page.tsx`. The page auto-updates as you edit the file.
+
+## Student ticket payments
+
+Student checkout is available at `/tickets/student` and uses Paystack InlineJS,
+so payment opens in a modal without redirecting away from the website. Copy
+`.env.example` to `.env.local`, add a Paystack test secret key and ticket price,
+then set `STUDENT_TICKET_SALES_ENABLED=true` to enable checkout.
+
+The ticket amount is configured in whole Kenyan shillings and converted to
+Paystack's subunit amount on the server. The Paystack secret is server-only and
+must never use a `NEXT_PUBLIC_` prefix.
+
+Configure this webhook URL in the Paystack dashboard:
+
+```text
+https://pycon.ke/api/payments/paystack/webhook
+```
+
+For local webhook testing, expose the local server through an HTTPS tunnel and
+temporarily register the resulting `/api/payments/paystack/webhook` URL in the
+Paystack test dashboard. The endpoint validates the `x-paystack-signature`
+header before acknowledging an event.
+
+Run the project checks with:
+
+```bash
+npm test
+npm run lint
+npm run build
+```