feat: expose response headers from query composables

[zedrdave]

Adds responseHeaders shallowRef to QueryReturn and LazyQueryReturn types, allowing consumers to access response headers (e.g., X-Pagination for pagination metadata) from the last successful query.

Changes

• buildQueryFn accepts optional headersSink parameter to capture response headers
• useEndpointQuery creates and returns a responseHeaders shallowRef
• useEndpointLazyQuery exposes responseHeaders populated on fetch()
• QueryReturn and LazyQueryReturn types updated with responseHeaders: ShallowRef<Record<string, string>>
• New test file: tests/unit/response-headers.test.ts (8 tests)
• Version bump: 0.21.0 → 0.21.1

[Copilot]

Pull request overview

This PR exposes response headers from the most recent successful query execution via a new responseHeaders shallowRef on both query composables’ return types, enabling consumers to read metadata such as pagination headers.

Changes:

• Captures axios response headers inside buildQueryFn and surfaces them on useEndpointQuery / useEndpointLazyQuery.
• Extends QueryReturn / LazyQueryReturn types with responseHeaders.
• Adds unit tests covering header exposure and updates package version + changelog entries.

Reviewed changes

Copilot reviewed 5 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
tests/unit/response-headers.test.ts	Adds tests validating responseHeaders behavior for query and lazy query flows.
src/openapi-query.ts	Implements header capture via headersSink and returns responseHeaders from composables/types.
src/index.ts	Re-exports ShallowRef type for consumers.
package.json	Bumps package version.
package-lock.json	Updates lockfile version fields to match package version bump.
CHANGELOG.md	Adds release notes for the new responseHeaders API.