content(guide): clarify visa D vs residence permit and residence application routes

Update the Student Welcome Guide residence pages (EN/MK/SI):

- visa-and-residence-explained: clarify that visa D mainly applies to
  study exchanges (e.g. Erasmus, up to one year) and is handled only by
  the embassy, while degree students use the temporary residence permit
  decided by the administrative unit (a permit, not a "visa").
- where-to-apply-for-residence: explain that the embassy only forwards
  the application to the administrative unit (slower, costlier); present
  applying directly at the administrative unit as usually faster and
  cheaper with the same documents; replace vague checklist prompts with
  concrete facts (appointment contact, standard document list, official
  Slovenian translation, certification, criminal-record recency, fees);
  keep the cautious lawful-stay wording and add a warning about leaving
  Slovenia while the application is pending.

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

en/student-welcome-guide/visa-and-residence-explained/index.html

@@ -227,7 +227,9 @@
 
                 <h2>Visa D</h2>
 
-                <p>A long-stay visa D is a separate document, generally used for a stay longer than 90 days and up to one year where its conditions are met. It is not automatically the correct or necessary route for every degree student.</p>
+                <p>A long-stay visa D is a separate document, generally used for a stay longer than 90 days and up to one year where its conditions are met. In practice it is mainly relevant for students coming on a study exchange, for example Erasmus, for up to one year. This route is handled only by the Slovenian Embassy in Skopje and cannot be arranged through a Slovenian administrative unit.</p>
+
+                <p>Students enrolled in a full degree programme in Slovenia normally do not use visa D. Their route is the temporary residence permit for study described below, which is decided by the Slovenian administrative unit (upravna enota). Many people loosely call this a &ldquo;visa&rdquo;, but legally it is a residence permit, not a visa.</p>
 
                 <h2>Temporary residence permit for study</h2>