Add Map Theme Editor with save/load functionality

- Enhanced maplibre-test.html into a full theme editor
- Added 6 preset themes (Fantasy Dark, Enchanted Forest, Desert Oasis, etc.)
- Save custom themes with names to localStorage
- Load saved themes with color preview dots
- "Set as Active Game Theme" applies colors to HikeMap
- index.html now reads active theme from localStorage on load
- Real-time preview of color changes on the map

Access at /maplibre-test.html

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

index.html

@@ -4375,8 +4375,8 @@
         // =====================
         // FANTASY MAP STYLE
         // =====================
-        // Default fantasy colors (can be customized via settings)
-        const mapColors = {
+        // Default fantasy colors (can be customized via Theme Editor)
+        const defaultMapColors = {
             land: '#1a1a2e',
             water: '#0f3460',
             roads: '#e94560',
@@ -4384,6 +4384,19 @@
             parks: '#1b4332'
         };
 
+        // Load active theme from localStorage (set by Theme Editor)
+        let mapColors = { ...defaultMapColors };
+        try {
+            const savedTheme = localStorage.getItem('hikemap_active_theme');
+            if (savedTheme) {
+                const parsed = JSON.parse(savedTheme);
+                mapColors = { ...defaultMapColors, ...parsed };
+                console.log('Loaded custom map theme:', mapColors);
+            }
+        } catch (e) {
+            console.log('Using default map colors');
+        }
+
         // Build the fantasy map style
         function buildFantasyStyle(colors, use3dBuildings = true) {
             return {