Initial Mebbling hub implementation

lib/rate-limit.ts

@@ -0,0 +1,8 @@
+const visits = new Map<string, { count: number; resetAt: number }>();
+
+export function withinRateLimit(key: string, limit = 30, windowMs = 60_000) {
+  const now = Date.now(); const record = visits.get(key);
+  if (!record || record.resetAt <= now) { visits.set(key, { count: 1, resetAt: now + windowMs }); return true; }
+  if (record.count >= limit) return false;
+  record.count += 1; return true;
+}