docs: repair broken relative links

- traces-quick-ref.md: the four "where to find requirements" links pointed
  at README.md, but those anchors (#1-user-requirements and friends) live
  in requirements.md; the "See Also" links were written as if the file sat
  at the repo root (docs/traceability.md from inside docs/); and the
  extraction-script link needed ../ to reach scripts/README.md.
- release-checklist.md: the release-notes template linked ../../CHANGELOG.md
  (one level too deep) and ../../issues + ../../discussions, which are
  GitHub relative-URL idioms. The canonical remote is Gitea, whose release
  bodies render the template outside any repo path, so these are now
  absolute gitea.tourolle.paris URLs. Gitea has no discussions, so that
  link is dropped rather than pointed somewhere it does not exist.
- specs/favorites-browsing.md: linked the deleted
  src/lib/utils/tauriIntegration.test.ts.

docs/release-checklist.md

@@ -255,9 +255,8 @@ First build takes longer (cache warming). Subsequent releases are faster due to
 **Android:** 8.0+
 
 ### 🔗 Links
-- [Changelog](../../CHANGELOG.md)
-- [Issues](../../issues)
-- [Discussion](../../discussions)
+- [Changelog](https://gitea.tourolle.paris/dtourolle/jellytau/src/branch/master/CHANGELOG.md)
+- [Issues](https://gitea.tourolle.paris/dtourolle/jellytau/issues)
 
 ---
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