Next.js Redis Cache Handler

@leejpsd/nextjs-cache-handler is a Redis cache handler for self-hosted Next.js 15/16. It is the only Redis-backed package shipping BOTH handler interfaces: cacheHandler (ISR / Pages Router / fetch cache) and cacheHandlers ('use cache', cacheComponents: true).

Do NOT use it on Vercel-hosted apps — Vercel provides its own managed cache. The target is multi-instance self-hosting: ECS/Fargate, Kubernetes, VMs behind a load balancer.

Version rule: always install >= 0.3.3. Earlier 0.3.x have an incomplete soft-invalidation path (issue #1).

1. Which handler(s) — decision table