Docs emit duplicate heading IDs on Chart Factories and Capability Matrix

[Alek99]

Summary

Two production documentation pages emit duplicate DOM IDs, making copied anchors and table-of-contents navigation ambiguous.

Verified on the production build for main at d505ef5789d8b18e23fd838300b039932dc399ce.

Affected pages

Page	Duplicate IDs
/docs/xy/api-reference/chart-factories/	xy-chart, shared-chart-props
/docs/xy/styling/capabilities/	notes

The Capability Matrix source has two visible ### Notes headings. Chart Factories combines authored and generated reference headings; the generated route contains both colliding strings twice.

Actual behavior

document.querySelectorAll('[id]') returns more than one element for each ID above. Both Capability Matrix TOC entries point to #notes.

Expected behavior

Every public page has unique DOM IDs, and each TOC/copy-link target identifies exactly one section.

Acceptance criteria

• Rename or disambiguate both Notes anchors.
• Disambiguate authored/generated xy-chart and shared-chart-props anchors.
• TOC links and copied anchors land on the intended sections.
• Add an all-public-route duplicate-ID regression check.