Fix Cloudflare Worker Durable Object Backend Contract and Rate Limiting

I am seeking a skilled developer to resolve issues with my multi-tenant SDK, specifically focusing on fixing the communication between Cloudflare Workers, Durable Objects, and my FastAPI backend. The task involves ensuring proper header and authentication setup to fetch policies and enforce rate limiting across different scopes.

Deliverables
Fix Worker DO Backend contract
Ensure Durable Object fetches policies
Verify end-to-end rate limiting enforcement
Provide test validation steps