feat(core/dfn-index): data-noindex for external terms

[marcoscaceres]

Closes #4895

[Copilot]

Pull request overview

Adds a granular opt-out (data-noindex) so authors can prevent specific external data-cite links from being listed under “Terms defined by reference” in the dfn index (per #4895).

Changes:

• Skip a[data-cite][data-noindex] entries when collecting the external terms index.
• Strip data-noindex during export cleanup (similar to other ReSpec-only attributes).
• Add a spec test for the new exclusion behavior and add French l10n strings for the dfn index headings.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/core/dfn-index.js	Implements data-noindex exclusion in external term collection; adds export cleanup; adds fr l10n strings.
tests/spec/core/dfn-index-spec.js	Adds coverage ensuring data-noindex terms are omitted from the external index.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[marcoscaceres]

@copilot Can you confirm all your feedback has been addressed? Can you fix anything that was not addressed?

[marcoscaceres]

@copilot Can you confirm all your feedback has been addressed? Can you fix anything that was not addressed?

[Copilot]

@copilot Can you confirm all your feedback has been addressed? Can you fix anything that was not addressed?

Yes, all feedback has been addressed. The single review comment (about the test passing vacuously on an empty index) was fixed in 904170d. The test now has three positive assertions alongside the negative one:

1. expect(externalIndex).toBeTruthy() — index section exists
2. expect(terms.length).toBeGreaterThan(0) — at least one term collected
3. expect(terms).toContain("Event interface") — a known term is present

There are no other outstanding review items.