BREAKING: Make module ESM only

[fb55]

• Set type: module, update tsconfig to es2022/nodenext
• Output to dist/ instead of lib/, remove dual CJS/ESM build
• Simplify exports to ESM-only
• Migrate Jest to Vitest
• Bump all deps to latest majors (boolbase ^2, css-select ^7, css-what ^8, domelementtype ^3, domhandler ^6, domutils ^4)
• Import isTag from domhandler (no longer re-exported by domutils)
• Use _compileUnsafe instead of removed _compileToken from css-select
• Remove re-export of removed aliases/filters/pseudos from css-select
• Add engines >= 20.19.0
• Add publish workflow (npm + JSR), SECURITY.md

BREAKING CHANGE: This package is now ESM-only.

[Copilot]

Pull request overview

This PR migrates the package to an ESM-only distribution, modernizes the TypeScript build output (to dist/ with nodenext), upgrades major dependencies, and switches the test runner from Jest to Vitest while updating CI/publish automation accordingly.

Changes:

• Convert build/packaging to ESM-only (type: module, exports updated, dist/ output, remove dual CJS/ESM build).
• Upgrade selector/DOM dependency majors and adjust code to updated APIs (domhandler isTag, css-select _compileUnsafe, etc.).
• Migrate tests and CI from Jest to Vitest; add publish workflow + SECURITY.md.

Reviewed changes

Copilot reviewed 11 out of 14 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tsconfig.json	Switch TS output/targets to ESM (es2022, nodenext) and emit to dist/.
package.json	Mark package ESM-only, simplify exports, update scripts to Vitest, bump major deps, add Node engine.
src/index.ts	Update css-select compilation API and isTag usage; introduce adapter passed to prepareContext.
src/index.spec.ts	Update test imports for ESM (.js specifiers) and Vitest.
src/helpers.spec.ts	Update test runner imports and ESM .js specifier.
test/tools/sizzle-testinit.ts	Update htmlparser2 API usage and isTag import; migrate assertions to Vitest.
test/sizzle.spec.ts	Migrate to Vitest, update htmlparser2 API, and swap to domhandler isTag.
test/advanced-selectors.spec.ts	Migrate to Vitest and update ESM import path for select.
.github/workflows/nodejs-test.yml	Run Vitest instead of Jest; update Node matrix.
.github/workflows/publish.yml	Add tag-based publish workflow for npm + JSR with generated jsr.json.
SECURITY.md	Add security reporting policy document.
.gitignore	Ignore dist/ output and generated jsr.json.
biome.json	Bump Biome schema reference.

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