🔧 Replace ESLint and Prettier with oxlint and oxfmt

- 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

README.md

@@ -7,20 +7,38 @@ Pattern matching for TypeScript/ESM environments (F#-style, not regex).
 - **Build:** `npm run build`
 - **Test:** `npm run test`, `npm run test:ci`
 - **Checks:** `npm run check`, `npm run fix`
+- **Format/Fix:** `npm run fix:oxfmt`, `npm run fix:oxlint`
+
+### Tooling
+
+- **TypeScript 7** — type checker and build (`tsc`).
+- **node --test** + `--experimental-strip-types` — test runner (Node 22.6+, flag dropped on Node 24).
+- **c8** — code coverage for `test:ci`.
+- **oxlint** — Rust-based linter.
+- **oxfmt** — Rust-based formatter (Prettier-compatible).
+- **cspell** — spell checking.
+- **sort-package-json** — keep `package.json` keys alphabetized.
+- **lefthook** — git pre-commit hooks.
+
+### Requirements
+
+- Node.js >= 22.6 (>= 24 recommended; `--experimental-strip-types` is unflagged on 24).
 
 ## VSCode integration
 
-- Debugging
-- Running tests
+- Recommended extensions: see `.vscode/extensions.json` (oxc, cspell).
+- TypeScript 7 is used via `typescript.tsdk` pointing at `node_modules/typescript/lib`.
+- oxc extension provides oxlint squiggles and oxfmt format-on-save.
 
 ## Workflows
 
-- Version updates
-- Changelog automation
-- Publishing
+- Version updates via `npm version`.
+- Publishing via GitHub Actions on tagged commits (see `.github/workflows/ci.yml`).
+- Changesets is available as a devDependency for changelog automation if desired.
 
 ## Contribution guidelines
 
-- Commit signing (GPG)
-- How to set up commit message template
-- Reference to commit-message-template
+- Commit signing (GPG).
+- Set up commit message template: `npm run use:git-commit-message`.
+- See `commit-message-template`.
+- Type-only tests use `expect-type`'s `expectTypeOf(...)` inside `node --test` cases.