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

docker-compose.yml

@@ -0,0 +1,28 @@
+services:
+  app:
+    build: .
+    ports:
+      - "${APP_PORT:-3001}:3000"
+    env_file: .env
+    environment:
+      - DATABASE_URL=postgresql://sub2apipay:${DB_PASSWORD:-password}@db:5432/sub2apipay
+    depends_on:
+      db:
+        condition: service_healthy
+    restart: unless-stopped
+
+  db:
+    image: postgres:16-alpine
+    environment:
+      POSTGRES_USER: sub2apipay
+      POSTGRES_PASSWORD: ${DB_PASSWORD:-password}
+      POSTGRES_DB: sub2apipay
+    volumes:
+      - pgdata:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U sub2apipay"]
+      interval: 5s
+    restart: unless-stopped
+
+volumes:
+  pgdata: