chore: smoother dev workflow, release script and package READMEs

[BatLeDev]

Makes the lib easier to build, test, release and read, separately from the dev-env work.

Build

• build-types compiles the generator's own imports: a fresh checkout, or a new file imported by build.ts, no longer fails with ERR_MODULE_NOT_FOUND (the manual build-tsc bootstrap is gone from CONTRIBUTING).
• build-tsc removes the build outputs whose source was deleted (scripts/clean-orphans.mts): tsc never does it and npm publish ships every **/*.js, so a deleted module (e.g. lib-vue selection-filters) would have been published again.
• build no longer runs eslint --fix.

Hooks and CI

• husky 8 → 9; commit-msg passes "$1".
• quality = build + lint + test, in that order: tests import the built .js, the old pre-push tested a possibly stale build. Used by pre-push, prepublishOnly and the new pull request workflow.
• lint no longer fixes files (fixes made at commit time were not staged); lint-fix does.
• site.test.js was never run (the glob only takes .ts): now site.test.ts.
• engines >=22.6, needed by --experimental-strip-types.

Release

• npm run release <package> <patch|minor|major> bumps the version and creates the chore: release lib-<name> <version> commit (package.json + lockfile), then git push and npm publish -w packages/<package> as before. A plain npm version hook cannot do it: npm updates the lockfile after its version hooks.

Docs

• A README per package (npm pages were empty), verified against the sources; the root README becomes an index. Removed APIs dropped (initSession, colors.js, Nuxt module, stringify export, old @data-fair/lib/... paths).
• upgrade-scripts skill: locks.start(db), not locks.init(db). lib-vuetify description: Vuetify 4.

Fixes

• Drop main: index.js from the packages without a root entry (common-types, node, processing-dev, utils, vue).
• ESLint deprecation messages of lib-utils point to the lib-* packages.

Cleanup

• Remove the stale installed skill copies (.agents/, .claude/skills/, skills-lock.json); skills/ is the source.
• .gitignore: .superpowers/, .claude/settings.local.json.

Not included: debug (lib-node, lib-express, lib-vue) and prom-client (lib-express) are imported without being declared as dependencies.