Implement $hasAny operator for any-of array-containment matching

[Copilot]

Thanks for the feedback on #331. This PR implements the $hasAny operator as a sibling to $has, providing explicit any-of array-containment semantics.

Original PR: #331
Triggering review: #331 (comment)

Changes Made

• Object mode (src/utils/metadataUtil.js): Added $hasAny case in buildOperatorChecks — compiles to Array.isArray(v) && expectedValues.some(x => v.includes(x)).
• Raw-buffer mode (src/utils/metadataUtil.js): Added $hasAny branch in buildMatcherTreeChild — anchors on the "key":[ opener and calls indexOfSameLevel for each pre-serialized value pattern, short-circuiting on the first hit.
• IndexMatcher (src/IndexMatcher.js): Added isLoneHasAnyArray helper and $hasAny handling in findDiscriminant — registers the matcher under each expected value as a discriminant key, enabling O(1) routing when any document array element matches (deduplication handled by the existing called set in forEachMatch).
• Docs: Updated streams.md, api.md, dcb.md, and changelog.md to document $hasAny alongside $has.
• Tests: Added object-mode and raw-buffer-mode tests in test/metadataUtil.spec.js and discriminant registration/lookup tests in test/IndexMatcher.spec.js.

Usage

// matches events whose payload.tags array contains 'course:1' OR 'student:9'
{ payload: { tags: { $hasAny: ['course:1', 'student:9'] } } }

[albe]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved. Two conflicts in the merge with origin/main:

• docs/changelog.md: kept the condensed 1.4.0 format and added the new "Breaking:" bullet from main.
• test/IndexMatcher.spec.js: retained both the new $hasAny tests from our branch and the $has edge-case tests added on main.

All 687 tests pass.

[coveralls]

coverage: 98.299% (+0.01%) from 98.288% — copilot/wip-implement-hasany-operator into main