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

src/api/track/get_obstable.php

@@ -0,0 +1,46 @@
+<?php
+// /api/track/get_obstacle.php
+header('Content-Type: text/html; charset=utf-8');
+
+// Read JSON POST body
+$input = json_decode(file_get_contents('php://input'), true);
+$id = $input['id'] ?? '';
+
+if (!$id) {
+    http_response_code(400);
+    echo "<h3>Error</h3><p>Invalid obstacle id.</p>";
+    exit;
+}
+
+// TODO: Replace this with DB lookup (mysqli) by id.
+// For demo return stubbed content:
+$fake = [
+    'obst-camp' => [
+        'title' => 'Base Camp',
+        'img' => '/assets/images/camp.jpg',
+        'difficulty' => 'easy',
+        'desc' => 'Flat campsite with shade and water point.'
+    ],
+    'obst-water' => [
+        'title' => 'Water Crossing',
+        'img' => '/assets/images/water.jpg',
+        'difficulty' => 'hard',
+        'desc' => 'Deep crossing after heavy rain, check depth first.'
+    ]
+];
+
+$data = $fake[$id] ?? null;
+
+if (!$data) {
+    http_response_code(404);
+    echo "<h3>Not found</h3><p>No details for '{$id}'.</p>";
+    exit;
+}
+
+// render HTML snippet for Magnific
+?>
+<img src="<?= htmlspecialchars($data['img']) ?>" alt="<?= htmlspecialchars($data['title']) ?>" style="width:100%; height:220px; object-fit:cover; border-radius:6px; margin-bottom:12px;">
+<h3><?= htmlspecialchars($data['title']) ?></h3>
+<span class="difficulty-badge <?= htmlspecialchars($data['difficulty']) ?>"><?= htmlspecialchars(ucfirst($data['difficulty'])) ?></span>
+<div class="description" style="margin-top:10px;"><?= htmlspecialchars($data['desc']) ?></div>
+<?php