A usage circuit breaker for Cloudflare Workers

Description

I run 3mins.news (https://3mins.news), an AI news aggregator built entirely on Cloudflare Workers. The backend has 10+ cron triggers running every few minutes — RSS fetching, article clustering, LLM calls, email delivery. The problem: Workers Paid Plan has hard monthly limits (10M requests, 1M KV writes, 1M queue ops, etc.). There's no built-in "pause when you hit the limit" — CF just starts billing overages. KV writes cost $5/M over the cap, so a retry loop bug c