feat: Increase spider distance multiplier for better marker separation

- Increased spiderfyDistanceMultiplier from 2 to 3.5
- Provides much better separation when overlapping markers are clicked
- Markers now spread out 3.5x the default distance for easier clicking

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

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

assets/js/map.ts

@@ -578,7 +578,7 @@ let MapAPRSMap = {
           usual: '#222',
           highlighted: '#f00'
         },
-        spiderfyDistanceMultiplier: 2
+        spiderfyDistanceMultiplier: 3.5
       });
 
       // Add click handler for spiderfied markers