[AriaEdo]

Summary

Follow-ups to #1871 (changelog sourced from the docs MDX):

• Card body top spacing — the card body only reset the top margin of a leading h2. Docs entries often open with a list, which kept the prose margin-top (22.5px desktop / 17.5px mobile), so the content sat ~43px below "View on GitHub" instead of 20px. Now .changelog-entry-card-body > :first-child drops its top margin, whatever the element is.
• Product name as a tag — the <Update description> value (product name) moves from the eyebrow above the title into the tag list, as the first pill ahead of the type tags (Fix, AX/DX/UX, …). The data model is unchanged (product is still parsed separately).
• Date as the kicker — the release date takes the freed kicker slot above the title, in the kicker style (clay smallcaps, 8px above the title). The tags move up into the date's old place under the title, and the changelog-entry-nav-date-row wrapper is removed.

Sidebar order is now: date (kicker) → title → tags.

Notes

• Page search already matches tag text, so the product name stays searchable; search results still show title + date correctly.
• /changelog.md still lists only the type tags (unchanged).

Test plan

• All 24 local cards: first body child has margin-top: 0 (5 lead with UL, 19 with P)
• Header → content gap is 20px on desktop (1440) and mobile (390)
• All 24 cards render the product tag first; no .changelog-entry-nav-product left
• Date renders as kicker above the title on desktop and mobile; tags 16px under the title
• Search for datumctl / load balancer returns results with title + date
• astro check: 0 errors · npm run test:changelog: 8/8 pass · Prettier/ESLint clean (lint-staged)
• Visual check on the preview deploy (desktop + mobile)
• Not covered locally: entries without a product, or whose body opens with h2/pre