Roll out "Photos from the event" gallery to all event posts (EN/MK/SI)

- Added the reusable lightbox gallery block to all 9 event posts in every
  language (27 pages): shows 5 thumbnails + "+N more", opens the full-screen
  viewer with the whole photo set
- Inserted inside <article> (before the author footer where present) so it
  never breaks the sidebar/article flex layout
- Handled 3 SI posts that were missing their </article> tag by anchoring on
  the newsletter section instead

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

en/projects/in-memory-of-frosina-kulakova/index.html

@@ -229,6 +229,15 @@
 
                 <p>Rest in peace, Frosina. 🕊️🙏🏻</p>
             </div>
+
+                <section class="event-gallery">
+                    <h2 class="event-gallery-title">Photos from the event</h2>
+                    <div class="event-gallery-grid js-lightbox">
+                        <button type="button" class="eg-thumb" data-full="../../../images/frosina-1.webp" data-caption="In Memory of Frosina Kulakova"><img loading="lazy" decoding="async" src="../../../images/frosina-1.webp" alt="In Memory of Frosina Kulakova — photo 1"></button>
+                        <button type="button" class="eg-thumb" data-full="../../../images/frosina-2.webp" data-caption="In Memory of Frosina Kulakova"><img loading="lazy" decoding="async" src="../../../images/frosina-2.webp" alt="In Memory of Frosina Kulakova — photo 2"></button>
+                        <button type="button" class="eg-thumb" data-full="../../../images/frosina-3.webp" data-caption="In Memory of Frosina Kulakova"><img loading="lazy" decoding="async" src="../../../images/frosina-3.webp" alt="In Memory of Frosina Kulakova — photo 3"></button>
+                    </div>
+                </section>
         </article>
         <section class="newsletter-cta">
             <div class="container">