Add Student Welcome Guide, legal pages, and working newsletter

Student Welcome Guide (Phase 1):
- Landing + 5 topic pages (journey, bachelor, master, deadlines, eVS)
  in EN/SI/MK, reusing the article auto-TOC
- New css/pages/_guide.css components and a 3:1 hero image placeholder
- Functional client-side "Build my route" tool (student-guide.js)
- "Student Welcome Guide" menu link wired site-wide

Legal pages:
- Trilingual Privacy Policy and Cookie Policy (GDPR-oriented,
  MailerLite disclosed, IP RS complaint route)
- Footer legal strip + Organisation column links wired site-wide,
  depth-aware, plus header/footer templates

Newsletter:
- MailerLite subscribe handler in main.js upgrades both form variants
  on every page: validation, double opt-in, inline trilingual status
- Subscribe status styles in css/pages/_projects.css

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

css/main.css

@@ -31,4 +31,5 @@
 @import 'pages/_projects.css';
 @import 'pages/_article.css';
 @import 'pages/_about.css';
-@import 'pages/_timeline.css';
+@import 'pages/_timeline.css';
+@import 'pages/_guide.css';