fix: disable all map options by default except clustered markers

- Set showEvents to false by default
- Set showWaterQuality to false by default
- Set showHeatmap to false by default (already was)
- Set showHotspots to false by default (already was)
- Keep showClusters as true (only enabled option)

Users can now enable features as needed via map filters

src/pages/MapPage.tsx

@@ -20,8 +20,8 @@ export function MapPage() {
   const [showClusters, setShowClusters] = useState(true);
   const [showHeatmap, setShowHeatmap] = useState(false);
   const [showHotspots, setShowHotspots] = useState(false);
-  const [showEvents, setShowEvents] = useState(true);
-  const [showWaterQuality, setShowWaterQuality] = useState(true);
+  const [showEvents, setShowEvents] = useState(false);
+  const [showWaterQuality, setShowWaterQuality] = useState(false);
   const [hotspots, setHotspots] = useState<HotspotWithSeverity[]>([]);
   const [isLoadingHotspots, setIsLoadingHotspots] = useState(false);
   const [reports, setReports] = useState<Report[]>([]);