feat: require Node.js 22 or newer

[lan17]

Summary

• require Node.js >=22.0.0 in the published package contract
• update the README to recommend a currently supported LTS release for production
• pin the packed-consumer CI proof to exact Node.js 22.0.0
• keep development, unit, build, declaration, and Redis integration coverage on Node.js 24

Why

Node.js 20 reached end of life on March 24, 2026, but DialCache still advertised and tested it. A floating Node 20 package check also did not prove the bottom of the declared range. This makes the maintained runtime contract explicit without tying consumer support to the development toolchain's higher minor-version requirements.

Closes #34

Compatibility

This is a pre-v1 runtime-support change. Consumers running Node.js 20 must upgrade to a supported Node.js 22 or newer runtime before adopting the next DialCache minor release.

There are no changes to DialCache runtime APIs, cache keys, Redis protocol, stored values, or invalidation behavior. Mixed DialCache package versions remain data/protocol compatible; the only migration boundary is the application process runtime.

Release note

DialCache now requires Node.js 22.0.0 or newer. Production deployments should use a currently supported LTS release.

Validation

• Node.js v24.18.0: corepack pnpm check — 278 unit tests, coverage, typecheck, ESM/CJS builds, declarations, and packed consumers passed
• Node.js v24.18.0: corepack pnpm test:integration — all 73 Redis 6.2, Valkey 8, and Redis Cluster cases passed
• Node.js v24.18.0: corepack pnpm audit --prod — no known vulnerabilities
• Node.js v22.0.0: corepack pnpm test:package — packed ESM/CommonJS runtime and declaration consumers passed
• git diff --check