[fizzbeom]

Description

htmx.find(elt, selector) and htmx.findAll(elt, selector) ran plain CSS selectors on the element's root node, so they returned matches from the whole document. The reference page says the element is the one to "search within", and htmx 2 used elt.querySelectorAll(selector).

<div id="a"><span class="x"></span></div>
<div id="b"></div>
<script>
  htmx.findAll(document.getElementById('b'), '.x').length // 1 before, 0 now
</script>

Changes:

• findAll passes a new scoped flag to __findAllExt. With an element argument, plain selectors are matched within it. Extended selectors (closest, next, find, global, ...) still resolve relative to the element, as before. find returns the first result of findAll.
• hx-targets called htmx.findAll(ctx.sourceElement, selector) to resolve its selector like hx-target (whole document). It now calls a new internal API, api.findAllExt, so its behavior is unchanged. I added it to the two extension API lists that check_extension_api.py checks.

Corresponding issue: #4173

Testing

• New unit tests in test/tests/unit/__findAllExt.js: findAll(elt, selector) and find(elt, selector) only match within elt, and extended selectors still work relative to elt. The first two fail without the fix.
• New test/tests/ext/hx-targets.js (the extension had no tests): a plain selector outside the source element and an extended selector. The first test fails if hx-targets keeps calling htmx.findAll.
• npm run test: 1855 passed, 0 failed, 4 skipped, coverage 100% (Chromium, Windows).
• python3 src/scripts/content/check.py passes.

Checklist

• I have read the contribution guidelines
• I have targeted this PR against the correct branch (four-dev for htmx 4 source changes)
• This is either a bugfix, a documentation update, or a new feature that has been explicitly
  approved via an issue
• I ran the test suite locally (npm run test) and verified that it succeeded

This PR was generated with AI (Claude Code).