health: fix broken pages, add image dimensions, a11y & SEO wins

Site-wide health pass (excludes in-progress blog work). Verified with a
local server + headless browser: Timeline, homepage and gallery pages load
with zero console errors and no layout distortion.

Render bugs
- Timeline page (en/mk/si): fix ../../../ paths that overshot the site root,
  so the main stylesheet and hero image load again.
- Meet Student Slovenia 2023 (en/mk/si): remove a <figure> referencing
  event3-photo-11.png, an image that was never uploaded (broken image).

Performance
- Add intrinsic width/height to 1039 raster <img> tags to prevent layout
  shift (CLS); 450 SVGs correctly skipped. Add a global
  `img { max-width:100%; height:auto }` safety net so aspect ratio is
  preserved and images never overflow.
- Preload the homepage hero (LCP) image on en/mk/si.
- Load Font Awesome non-blocking (media=print/onload swap) with a <noscript>
  fallback, on 225 pages.

Accessibility
- Add aria-label to 57 unlabeled newsletter email inputs.
- Add an sr-only <h1> to the three "My Route" pages (had no h1).
- Add an .sr-only utility class.

SEO
- Add meta descriptions to legal/msos-hub/support pages (en/mk/si).

Note: MK/SI meta descriptions are machine-drafted and should be proofread
by a native speaker before considering them final.

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

en/student-welcome-guide/my-route/index.html

@@ -56,12 +56,13 @@
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap" rel="stylesheet">
     
     <!-- Font Awesome (for icons) -->
-    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css" integrity="sha512-DTOQO9RWCH3ppGqcWaEA1BIZOC6xxalwEsw9c2QQeAIftl+Vegovlnee1c9QX4TctnWMn13TZye+giMm8e2LwA==" crossorigin="anonymous" referrerpolicy="no-referrer" />
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css" integrity="sha512-DTOQO9RWCH3ppGqcWaEA1BIZOC6xxalwEsw9c2QQeAIftl+Vegovlnee1c9QX4TctnWMn13TZye+giMm8e2LwA==" crossorigin="anonymous" referrerpolicy="no-referrer" media="print" onload="this.media=&#39;all&#39;" /><noscript><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.5.1/css/all.min.css" integrity="sha512-DTOQO9RWCH3ppGqcWaEA1BIZOC6xxalwEsw9c2QQeAIftl+Vegovlnee1c9QX4TctnWMn13TZye+giMm8e2LwA==" crossorigin="anonymous" referrerpolicy="no-referrer" /></noscript>
 
     <!-- Correct path to the main CSS file -->
     <link rel="stylesheet" href="../../../css/main.css">
 </head>
 <body>
+<h1 class="sr-only">Your personal study route</h1>
 
     <!-- START_HEADER -->
 <header class="dropdown-header-navigation">