Blog: publish trilingual post 5 "Welcome Days" (EN/SI/MK)

Build the Welcome Days article in all three languages from the multilingual
source (# English / # Slovenščina / # Македонски sections + shared sources),
no machine translation. Date registered, SEO injected. Cards already existed.

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

tools/seo_inject.py

@@ -47,6 +47,7 @@ ARTICLE_DATES = {
     "blog/learning-slovene-where-to-start": {"published": "2026-07-28"},
     "blog/study-in-north-macedonia-government-scholarship-2026-2027": {"published": "2026-07-30"},
     "blog/ad-futura-scholarship-slovenia-2026": {"published": "2026-08-02"},
+    "blog/welcome-days-slovenian-universities-2026-2027": {"published": "2026-08-03"},
     "news/proof-of-means-updated-2026": {"published": "2026-08-01"},
     "projects/humanitarian-tournament-in-maribor": {"published": "2025-04-05"},
     "projects/in-memory-of-frosina-kulakova": {"published": "2025-02-08"},