content(projects): swap event placeholders for real photos + copy cleanup

Replace event-placeholder.svg with real .webp photos across all 2025-2026
event/project pages (EN/MK/SI), updating OG/Twitter/JSON-LD image refs,
inline article images, and content/events/*.md. Also Latinize EN/SI titles
(e.g. "Kafanska večer") and drop empty "In numbers" TOC sections.

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

en/index.html

@@ -335,7 +335,7 @@
                     </a>
                     <div class="card-content">
                         <p class="author">3 August 2026</p>
-                        <h3><a href="/en/blog/welcome-days-slovenian-universities-2026-2027/">Welcome Days for Bachelor's, Master's and Erasmus students in Slovenia</a></h3>
+                        <h3><a href="/en/blog/welcome-days-slovenian-universities-2026-2027/">Welcome Days for Bachelor&#x27;s, Master&#x27;s and Erasmus students in Slovenia</a></h3>
                     </div>
                 </article>
                 <article class="news-card" data-type="blog">