Expose docs/test front-door checks as a public npm script

[VladimirBrejcha]

Why this is real

CONTRIBUTING.md tells public patches to run test:broker-core, test:client, and test:harness-adoption. The contract tests that pin the public README, CONTRIBUTING tracks, CI shape, and now the issue/PR templates live under docs/test/ and run through the maintainer spec-only profile (node --test docs/test/*.test.mjs).

Independent review of PR #5 recorded that as a residual: a drive-by contributor who only follows the public-track npm scripts will not run those checks.

This project is Alpha, macOS-only, and needs Xcode. This ticket is only the public script wiring.

Expected

• package.json grows a public script such as test:docs that runs node --test docs/test/*.test.mjs.
• CONTRIBUTING.md public-patches track names that script for doc, README, and template changes.
• No harness session is required to run it.

Out of scope

• Moving those tests out of docs/test/
• Changing agent:complete or spec-only

[VladimirBrejcha]

Closed by merging #11.

Public npm run test:docs now runs node --test docs/test/*.test.mjs. CONTRIBUTING names it for doc, README, and template changes. A small maintainer follow-up will qualify that Ubuntu CI still does not run test:docs, and will add it to the PR template checklist.