- Drop .eslintrc.cjs and .prettierrc, add .oxlintrc.json and .oxfmtrc.json
- oxlint covers correctness/suspicious/perf/style/restriction categories
plus import and typescript plugins; oxfmt reads the same .prettierrc-style
options we had before
- Update lefthook.yml pre-commit jobs to run oxlint/oxfmt instead of
eslint/prettier
- Update .vscode/extensions.json (oxc replaces eslint/prettier/vitest) and
settings.json (oxc becomes the default formatter for TS/JS)
- Add 'oxlint', 'oxfmt', 'oxc', 'nodenext' to cspell dictionary
- Rewrite README 'Development' section to describe the new toolchain