Declarative 3-Tier Auth Pipeline for 673 API Routes

A developer built a composable request pipeline for a platform with 673 API routes across three access tiers: public (79), free API key (337), and paid subscription (255). The pipeline uses a higher-order function to enforce authentication, rate limiting, and quota checks declaratively at the route level. A CI guard fails the build if any protected route lacks the required wrapper, ensuring the access control matrix is always up to date.