Integrate v3 master: residence and health cluster (Batch 1)

Rewrites the six residence/health pages (visa-and-residence-explained,
student-residence-permit, where-to-apply-for-residence,
means-accommodation-address, rm-si-3-health-insurance,
healthcare-in-slovenia) to the deeper v3 English master, trilingual.
Adds backward-compatible generator support for per-page hero-image
placeholders and a "Sources and further information" section, plus
.guide-last-checked styling. Owner decisions applied (student work on
the study permit vs employment permit; sufficient means shown as
"check current"). SI/MK bodies are MSOS working translations pending
native proofread.

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

en/student-welcome-guide/study-cities/index.html

@@ -183,7 +183,7 @@
             <div class="article-body">
                 <div class="guide-meta">
                     <span class="guide-tag ">Applies to: students from Macedonia</span>
-                    <span class="guide-tag ">Last checked: 29 July 2026</span>
+                    <span class="guide-tag ">Last checked: 30 July 2026</span>
                     <span class="guide-tag is-annual">Update class: Annual</span>
                 </div>