chore: add release readiness audit

[mahyarmlk]

Summary

Add a release readiness audit document (docs/Release-Readiness.md) that analyzes all five workspace packages for npm publishing readiness, and makes package metadata publish-ready.

Why

Before the first npm release, the repository needs a clear picture of what is publishable, what metadata is missing, what risks exist, and what workflow changes are needed. This PR provides that audit without publishing or adding Changesets.

Changes

• docs/Release-Readiness.md — New audit document covering all five packages, npm scope risk, build outputs, export maps, files policy, release workflow recommendation, first alpha checklist, and current blockers
• LICENSE — Added MIT license file matching the package license fields
• packages/*/package.json — Added missing description and license fields to all five packages (core, dom, router, testing, server)
• package.json — Added pack:check script that dry-runs npm pack for all workspace packages
• README.md — Added link to the release readiness document near the roadmap section

Tests

• All 310 tests pass (127 core + 86 dom + 72 router + 21 testing + 4 server)
• pnpm typecheck passes
• pnpm build completes for all packages
• pnpm lint passes
• pnpm pack:check passes — all 5 packages produce correct tarball contents

Validation

rm -rf packages/*/dist examples/*/dist
pnpm test    # 310 passed
pnpm typecheck  # clean
pnpm build   # all packages
pnpm lint    # clean
pnpm pack:check  # all 5 packages pass

Remaining blockers

• Missing repository fields in package.json
• @intent npm scope availability not yet verified
• No release workflow (Changesets + GitHub Action)
• Server package maturity
• Version is 0.1.0 without alpha prerelease tag

Next recommended step

Confirm @intent npm org availability, then add Changesets for the first alpha release.