Swedish adaptation: Instegscertifikat and HAREC

- Editions replaced by INSTEG, HAREC and UPPGRADERING (Instegscertifikat -> HAREC)
- Question pool optional; simulator, homework tool and solutions switch off without one
- All UI strings, templates, renderers and project JS localised to sv-SE
  (decimal comma, Swedish non-breaking-space rules, Å/Ä/Ö in Morse table)
- DARC branding, membership CTA and German links removed; attribution footer added
- Page names centralised in src/pages.py
- README and docs rewritten in Swedish

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

assets/style-slide.css

@@ -1,5 +1,5 @@
 /**
- * DARC Theme based on:
+ * Theme based on:
  * A simple theme for reveal.js presentations, similar
  * to the default theme. The accent color is darkblue.
  *
@@ -386,12 +386,12 @@ section.has-dark-background h6 {
 }
 
 /*********************************************
-  * OWN ADDITIONS TO DARC THEME
+  * OWN ADDITIONS TO THE THEME
   *********************************************/
 
 /* Scalable Logo on bottom left */
 body:after {
-    background-image: url(images/50ohm_rus.svg);
+    background-image: url(images/50ohm_gray.svg);
     background-size: 8.5em 5em;
     position: fixed;
     bottom: 1em;