Add interactive Base 4 track map with Leaflet.js

- Created new track-map page with aerial image and SVG overlay
- Implemented custom rotated square markers with obstacle numbers
- Added admin edit mode for placing and repositioning markers
- Database migration for track_obstacles table
- Modal form for adding new obstacles (replaces browser alerts)
- Drag-to-reposition functionality with auto-save
- Color-coded markers (green/red/black/split) for difficulty levels
- Clickable popups showing obstacle details
- Added track-map to navigation menu and sitemap
- URL rewrite rule for clean /track-map URL

sitemap.xml

@@ -15,6 +15,11 @@
   <lastmod>2025-04-10T11:24:41+00:00</lastmod>
   <priority>0.80</priority>
 </url>
+<url>
+  <loc>https://4wdcsa.co.za/track-map</loc>
+  <lastmod>2025-12-12T00:00:00+00:00</lastmod>
+  <priority>0.80</priority>
+</url>
 <url>
   <loc>https://4wdcsa.co.za/trips.php</loc>
   <lastmod>2025-04-10T11:24:41+00:00</lastmod>