## What kind of change does this PR introduce?
Sync changelog from private supabase/changelog.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Changelog entries now come from the structured changelog repository.
* Added filters for change type, product stage, and self-hosted impact.
* Updated badge UI for affected products and change types with filter
links.
* Changelog detail sidebar now shows lifecycle stage, sunset dates, and
self-hosted impact (when available).
* **Improvements**
* Product category discovery and filtering now use affected products.
* Discussion links show only when legacy discussion data is present.
* RSS feeds and generated changelog markdown now use the updated
metadata.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Francesco Sansalvadore
7c20cc574c