feat: migrate payment provider to easy-pay, add order history and refund support

- Replace zpay with easy-pay payment provider (new lib/easy-pay/ module)
- Add order history page for users (pay/orders)
- Add GET /api/orders/my endpoint to list user's own orders
- Add GET /api/users/[id] endpoint for sub2api user lookup
- Add order status tracking module (lib/order/status.ts)
- Update config to support easy-pay credentials (merchant ID, key, gateway)
- Update PaymentForm and PaymentQRCode components for easy-pay flow
- Update pay page and admin page with new order management UI
- Update order service to support easy-pay, cancellation, and refund

start.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+set -e
+
+echo "Running database migrations..."
+PRISMA_BIN=$(find node_modules/.pnpm -path '*/prisma/build/index.js' -type f | head -1)
+
+if [ -n "$PRISMA_BIN" ]; then
+  node "$PRISMA_BIN" migrate deploy --config prisma.config.ts
+  echo "Migrations complete."
+else
+  echo "Warning: prisma CLI not found, skipping migrations."
+fi
+
+echo "Starting application..."
+exec node server.js