chore: align Node versions across engines, Dockerfile and CI

[BryanFRD]

Problem

Three different Node versions are in play:

• package.json:8-9 — "engines": { "node": ">=22.0.0" }, and the same floor in each package
• Dockerfile — FROM node:24-alpine for both the build and the runtime stage
• CI — the reusable Node workflow's default

So the published packages advertise support for Node 22, and nothing in this repo ever builds or tests on Node 22.

Why it matters

The servers are published to npm and installed by users via npx on whatever Node they happen to run. A Node 24-only API reaching the source compiles, ships, passes CI, and breaks for a Node 22 user at runtime — the one configuration nobody exercises. The engines floor is a promise the pipeline does not verify.

Proposed approach

Pick one of two, and make it consistent everywhere:

• Raise the floor: engines.node >= 24 across the root and all six packages, matching the image and CI. Simplest, but drops Node 22 users on the next publish, so it is a breaking change for them and needs a changelog note.
• Or keep >= 22 and add a Node 22 leg to the CI test matrix, so the promise is tested.

Either way @types/node and the tsconfig target should line up with the decision.

Acceptance criteria

• The engines floor, the Docker image tag, and the CI matrix agree.
• If the floor moves, it is called out as a breaking change in the release notes.