Initial commit: Lightning Lottery - Bitcoin Lightning Network powered lottery

Features:
- Lightning Network payments via LNbits integration
- Provably fair draws using CSPRNG
- Random ticket number generation
- Automatic payouts with retry/redraw logic
- Nostr authentication (NIP-07)
- Multiple draw cycles (hourly, daily, weekly, monthly)
- PostgreSQL and SQLite database support
- Real-time countdown and payment animations
- Swagger API documentation
- Docker support

Stack:
- Backend: Node.js, TypeScript, Express
- Frontend: Next.js, React, TailwindCSS, Redux
- Payments: LNbits

back_end/src/middleware/rateLimit.ts

@@ -0,0 +1,61 @@
+import rateLimit from 'express-rate-limit';
+
+/**
+ * Rate limiter for buy endpoint
+ * Max 10 calls per IP per minute
+ */
+export const buyRateLimiter = rateLimit({
+  windowMs: 60 * 1000, // 1 minute
+  max: 10,
+  message: {
+    version: '1.0',
+    error: 'RATE_LIMIT',
+    message: 'Too many purchase requests, please try again later',
+    retry_after: 60,
+  },
+  standardHeaders: true,
+  legacyHeaders: false,
+  // Skip failed requests - don't count them against the limit
+  skipFailedRequests: true,
+  // Use IP from request, ignore X-Forwarded-For in development
+  validate: { xForwardedForHeader: false },
+});
+
+/**
+ * Rate limiter for ticket status endpoint
+ * Max 60 calls per minute
+ */
+export const ticketStatusRateLimiter = rateLimit({
+  windowMs: 60 * 1000, // 1 minute
+  max: 60,
+  message: {
+    version: '1.0',
+    error: 'RATE_LIMIT',
+    message: 'Too many status requests, please try again later',
+    retry_after: 60,
+  },
+  standardHeaders: true,
+  legacyHeaders: false,
+  skipFailedRequests: true,
+  validate: { xForwardedForHeader: false },
+});
+
+/**
+ * General rate limiter
+ * Max 100 requests per minute
+ */
+export const generalRateLimiter = rateLimit({
+  windowMs: 60 * 1000, // 1 minute
+  max: 100,
+  message: {
+    version: '1.0',
+    error: 'RATE_LIMIT',
+    message: 'Too many requests, please try again later',
+    retry_after: 60,
+  },
+  standardHeaders: true,
+  legacyHeaders: false,
+  skipFailedRequests: true,
+  validate: { xForwardedForHeader: false },
+});
+