Unify Further Reading into one styled box (CF-3115)

- Template renders one Further Reading aside (essential-reading style)
  with author-curated list + auto-appended layers-of-protection pillar
- Removed separate Essential reading aside
- Migrated 10 articles' ## Further Reading sections into frontmatter
  further_reading: translationKey arrays
- Added further_reading i18n key in en/de/fr

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

content/en/is-tiktok-safe-for-kids.md

@@ -7,6 +7,10 @@ categories: ["safety"]
 author: "Agiliton"
 slug: "is-tiktok-safe-for-kids"
 translationKey: "is-tiktok-safe"
+further_reading:
+  - "france-social-media-ban"
+  - "denmark-social-media-ban"
+  - "germany-age-debate"
 ---
 
 TikTok is, for most children, the first social network they want and the last one parents feel confident about. That instinct is not misplaced. In 2026, the answer to "is TikTok safe for my child?" is: **it depends on your child's age, what you are willing to set up, and how much you are prepared to talk to them about what they see**.
@@ -88,9 +92,3 @@ Because DNS-level filtering comes up again and again in this guide, it is worth
 - **Our category layer** — on top of the ad/tracker baseline, the Child profile adds social media (including TikTok), adult, gambling, dating, and gaming categories, and enforces safe search on Google, Bing and DuckDuckGo.
 
 We trim the raw upstream lists from around 119,000 domains down to roughly 15-30,000, because a smaller, curated list is faster on mobile, uses less memory, and produces fewer accidental blocks on regional German and European sites. This trimming is the work that matters — the raw lists are public, the curation is the product.
-
-## Further Reading
-
-- [France Votes to Ban Social Media for Children Under 15](/en/france-social-media-ban-under-15/)
-- [Denmark Moves to Ban Social Media for Children Under 15](/en/denmark-social-media-ban-under-15/)
-- [Germany's Debate on Social Media Age Limits](/en/germany-social-media-age-debate/)